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  • 151.
    Levin, Martina
    et al.
    Naphtenics Research AB Nynäs Petroleum.
    Wiklund, Per
    Naphtenics Research AB Nynäs Petroleum.
    Arwin, Hans
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik.
    Adsorption and film growth of N-methylamino substituted triazoles on copper surfaces in dydrocarbon media2007Inngår i: Applied Surface Science, ISSN 0169-4332, E-ISSN 1873-5584, Vol. 254, s. 1528-1533Artikkel i tidsskrift (Fagfellevurdert)
  • 152.
    Lindquist, OPA
    et al.
    Linkoping Univ, Dept Phys & Measurement Technol, SE-58183 Linkoping, Sweden.
    Arwin, Hans
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik.
    Forsberg, Urban
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi, Materiefysik.
    Bergman, JP
    Linkoping Univ, Dept Phys & Measurement Technol, SE-58183 Linkoping, Sweden.
    Järrendahl, Kenneth
    Linköpings universitet, Tekniska högskolan.
    Optical characterization of 4H-SiC by variable angle of incidence spectroscopic ellipsometry2000Inngår i: Materials Science Forum, ISSN 0255-5476, E-ISSN 1662-9752, Vol. 338-3, s. 575-578Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A variable angle of incidence spectroscopic ellipsometer equipped with a compensator has been used to determine the dielectric functions in the 0.74 - 6 eV photon energy range of n-type bulk 4H-SiC with doping concentrations between 10(17) and 10(19) cm(-3). The resulting dielectric function for different SiC wafers depends on the doping concentration, especially around the absorption onset and higher photon energies. Measurements on different wafers with the same doping show good reproducibility. Simulations and preliminary measurements show that ellipsometry might be useful for thickness determination of thin (<1 m) homoepitaxial films.

  • 153. Lindquist, OPA
    et al.
    Arwin, Hans
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik.
    Henry, Anne
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi, Halvledarmaterial.
    Järrendahl, Kenneth
    Linköpings universitet, Tekniska högskolan.
    Infrared optical properties of 3C, 4H and 6H silicon carbide2003Inngår i: Materials Science Forum, Vols. 433-436, 2003, Vol. 433-4, s. 329-332Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Dielectric functions for 3C-, 4H- and 6H-silicon carbide in the infrared photon energy region have been obtained using spectroscopic ellipsometry. Using samples with the optic axes both parallel and perpendicular to the sample surface normal, both the ordinary and extra-ordinary dielectric function were probed. Phonon modes and optical anisotropy are shown in the dielectric spectra.

  • 154.
    Lindquist, O.P.A.
    et al.
    IFM Linköpings universitet.
    Schubert, Mattias
    Inst for Experimental Physics II University of Leipzig.
    Arwin, Hans
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik.
    Järrendahl, Kenneth
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi.
    Infrared to vacuum ultraviolet optical properties of 3C, 4H and 6H silicon carbide measured by spectroscopic ellipsometry2004Inngår i: Elsevier Science, ISSN 1626-3200, Vol. 455-456, s. 235-238Artikkel i tidsskrift (Fagfellevurdert)
  • 155.
    Lunca Popa, Petru
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten. LIST, Luxembourg.
    Sønderby, Steffen
    Linköpings universitet, Institutionen för fysik, kemi och biologi. Linköpings universitet, Tekniska fakulteten. Tribol Centre, Denmark; National Oilwell Varco Denmark IS, Denmark.
    Kerdsongpanya, Sit
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten. Rensselaer Polytech Institute, NY 12180 USA.
    Lu, Jun
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Arwin, Hans
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska fakulteten.
    Eklund, Per
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Structural, morphological, and optical properties of Bi2O3 thin films grown by reactive sputtering2017Inngår i: Thin Solid Films, ISSN 0040-6090, E-ISSN 1879-2731, Vol. 624, s. 41-48Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Bi2O3 thin films were grown using reactive RF sputtering from a metallic Bi target. The influence of various deposition parameters (substrate temperature, applied power on target and oxygen content in the working gas) on the morphology, structure and optical properties of films was investigated. Depending on the O-2/(Ar + O-2) ratio of the working gas, bismuth, delta-Bi2O3, alpha-Bi2O3 or a mixture of these phases can be deposited, with a narrow window for growth of [111]-oriented delta-Bi2O3 thin films. The delta-Bi2O3 phase is stable from room temperature up to 350 degrees C (in air), where an irreversible transition to alpha-Bi2O3 occurs. This phase transformation is also shown to occur during TEM sample preparation, because of the inherent heating from the ion-milling process, unless liquid -nitrogen cooling is used. (C) 2017 Published by Elsevier B.V.

  • 156.
    Lundqvist, Martin
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Molekylär Bioteknik. Linköpings universitet, Tekniska högskolan.
    Nygren, Patrik
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Molekylär Bioteknik. Linköpings universitet, Tekniska högskolan.
    Jonsson, Bengt-Harald
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Molekylär Bioteknik. Linköpings universitet, Tekniska högskolan.
    Broo, Klas
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan.
    Induction of structure and function in a designed peptide upon adsorption on a silica nanoparticle2006Inngår i: Angewandte Chemie International Edition, ISSN 1433-7851, E-ISSN 1521-3773, Vol. 45, nr 48, s. 8169-8173Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    No abstrack available.

  • 157.
    Lundén, H.
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska fakulteten. Electrooptical Systems, Swedish Defence Research Agency (FOI), Linköping, Sweden.
    Lopes, Cesar
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Kemi. Linköpings universitet, Tekniska fakulteten.
    Lindgren, Mikael
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Kemi. Linköpings universitet, Tekniska fakulteten. Department of Physics, Norwegian University of Science and Technology, Trondheim, Norway.
    Liotta, A.
    Laboratoire de Chimie, ENS de Lyon, Lyon, France.
    Chateau,, D.
    Laboratoire de Chimie, ENS de Lyon, Lyon, France.
    Lerouge,, F.
    Laboratoire de Chimie, ENS de Lyon, Lyon, France.
    Chaput,, F.
    Laboratoire de Chimie, ENS de Lyon, Lyon, France.
    Désert,, A.
    Laboratoire de Chimie, ENS de Lyon, Lyon, France.
    Parola,, S.
    Laboratoire de Chimie, ENS de Lyon, Lyon, France.
    Efficient reverse saturable absorption of sol-gel hybrid plasmonic glasses2017Inngår i: Optical materials (Amsterdam), ISSN 0925-3467, E-ISSN 1873-1252, Vol. 69, s. 134-140Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Monolithic silica sol-gel glasses doped with platinum(II) acetylide complexes possessing respectively four or six phenylacetylene units (PE2-CH2OH and PE3-CH2OH) in combination with various concentrations of spherical and bipyramidal gold nanoparticles (AuNPs) known to enhance non-linear optical absorption, were prepared and polished to high optical quality. The non-linear absorption of the glasses was measured and compared to glasses doped solely with AuNPs, a platinum(II) acetylide with shorter delocalized structure, or combinations of both. At 532 nm excitation wavelength the chromophore inhibited the non-linear scattering previously found for glasses only doped with AuNPs. The measured non-linear absorption was attributed to reverse saturable absorption from the chromophore, as previously reported for PE2-CH2OH/AuNP glasses. At 600 nm strong nonlinear absorption was observed for the PE3-CH2OH/AuNPs glasses, also attributed to reverse saturable absorption. But contrary to previous findings for PE2-CH2OH/AuNPs, no distinct enhancement of the non-linear absorption for PE3-CH2OH/AuNPs was observed. A numerical population model for PE3-CH2OH was used to give a qualitative explanation of this difference. A stronger linear absorption in PE3-CH2OH would cause the highly absorbing triplet state to populate quicker during the leading edge of the laser pulse and this would in turn reduce the influence from two-photon absorption enhancement from AuNPs.

  • 158.
    Lundén, Hampus
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska fakulteten. Swedish Defence Research Agency FOI, Electrooptical Systems.
    Sol-Gel Glasses Doped with Pt-Acetylides and Gold Nanoparticles for Enhanced Optical Power Limiting2017Licentiatavhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    High power laser pulses can be a threat to sensors, including the human eye. Traditionally this threat has been alleviated by colour filters that blocks radiation in chosen wavelength ranges. Colour filters’ main drawback is that they block radiation regardless of it being useful or damaging, information is removed for wavelengths at which the filter protect. Protecting the entire wavelength range of a sensor would block or strongly attenuate the radiation needed for the operation of the sensor.

    Sol-gel glasses highly doped with Pt-Acetylide chromophores have previously shown high optical quality in combination with efficient optical power limiting through reverse saturable absorption1. These filters will transmit visible light unless the light fluence is above a certain threshold. A key design consideration of laser protection filters is linear absorption in relation to threshold level. By increasing chromophore concentration the threshold is lowered at the expense of higher linear absorption. This means that the user’s view is degraded through the filter.

    Adding small amounts of gold nanoparticles to the glasses resulted in an increase in optical power limiting performance. The optimal concentration of gold nanoparticles corresponded to a mean particle distance of several micrometers. The work in this licentiate thesis is about the characterization and explanation of this effect.

    The glasses investigated in this work were MTEOS Sol-Gel glasses doped with either only gold nanoparticles of varying shape and concentration, 50mM of PE2-CH2OH codoped with gold nanoparticles or 50mM of PE3-CH2OH codoped with gold nanoparticles. The glasses only doped with gold nanoparticles showed high optical power limiting performance at 532nm laser wavelength, but no optical power limiting at the fluences tested at 600nm. The PE2-CH2OH glasses codoped with gold nanoparticles showed an enhancement of optical power limiting at 600nm for the low gold nanoparticle concentration glasses. The enhancement was weakened or not present for higher concentrations. A similar enhancement above noise level for the PE3-CH2OH glasses was not found.

    A population model is used to give a qualitative explanation of the findings. The improvement in optical power limiting performance for the PE2-CH2OH glasses is explained by the gold nanoparticles helping to more quickly populate the highly absorbing triplet state during the rising edge of the laser pulse by enhancing two-photon absorption. The lack of any marked enhancement for the PE3-CH2OH glasses is explained by the PE3-CH2OH chromophore already being of sufficiently high performance to quickly populate the highly absorbing triplet state during the rising edge of the laser pulse. Further work is necessary to validate this model against other chromophores and improving its quantitative predictive power.

    Delarbeid
    1. Dispersion and self-orientation of gold nanoparticles in sol-gel hybrid silica - optical transmission properties
    Åpne denne publikasjonen i ny fane eller vindu >>Dispersion and self-orientation of gold nanoparticles in sol-gel hybrid silica - optical transmission properties
    Vise andre…
    2015 (engelsk)Inngår i: Journal of Materials Chemistry C, ISSN 2050-7526, E-ISSN 2050-7534, Vol. 3, nr 5, s. 1026-1034Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    Silica-based hybrid materials doped with gold nanoparticles (AuNPs) of different shapes were prepared with an adapted sol-gel technology (using MTEOS) and polished to high optical quality. Both spherical (23 and 45 nm in diameter) and bipyramidal (36, 50 and 78 nm in length) AuNPs were prepared and used as dopants. The AuNPs were functionalized with a novel silicone polymer for compatibilization with the sol-gel medium. The glass materials showed well defined localized surface plasmon resonance (SPR) absorbance from the visible to NIR. No redshifts in the spectra, due to the increase in doping concentration, were observed in the glasses, proving that no or very small SPR coupling effects occur. Spectroscopic Muller Matrix Ellipsometry showed that the shorter bipyramidal AuNPs (36 and 50 nm in length) have a clear preferred orientation in the MTEOS matrix, i.e. a tendency to be oriented with their long axis in the plane parallel to the glass surfaces. Dispersions of AuNPs have proven to be good optical power limiters that depend on particle size and geometry. The solid-state glass materials showed good optical power limiting at 532 nm for nanosecond pulses, which did not depend on the size or geometry of the AuNPs. In contrast to the observation at 532 nm, at 600 nm no optical limiting effect was observed. In these solids, as for dispersions of AuNPs, the optical limiting response is caused by scattering.

    sted, utgiver, år, opplag, sider
    Royal Society of Chemistry, 2015
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-114589 (URN)10.1039/c4tc02353f (DOI)000348300300017 ()
    Merknad

    Funding Agencies|Swedish Armed Forces; EOARD [FA8655-12-12106]; AFRL [FA8655-12-12106]

    Tilgjengelig fra: 2015-02-27 Laget: 2015-02-26 Sist oppdatert: 2019-04-29
    2. Long Distance Enhancement of Nonlinear Optical Properties Using Low Concentration of Plasmonic Nanostructures in Dye Doped Monolithic Sol-Gel Materials.
    Åpne denne publikasjonen i ny fane eller vindu >>Long Distance Enhancement of Nonlinear Optical Properties Using Low Concentration of Plasmonic Nanostructures in Dye Doped Monolithic Sol-Gel Materials.
    Vise andre…
    2016 (engelsk)Inngår i: Advanced Functional Materials, ISSN 1616-301X, E-ISSN 1616-3028, Vol. 26, nr 33, s. 10Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    Monolithic sol-gel silica composites incorporating platinum-based chromophores and various types of gold nanoparticles (AuNPs) are prepared and polished to high optical quality. Their photophysical properties are investigated. The glass materials show well-defined localized surface plasmon resonance (SPR) absorbance from the visible to NIR. No redshifts of the AuNP plasmon absorption peaks due to the increase in nanoparticle doping concentration are observed in the glasses, proving that no or very small SPR coupling effects occur between the AuNPs. At 600 nm excitation, but not at 532 nm, the AuNPs improve the nonlinear absorption performance of glasses codoped with 50 × 10−3 m of a Pt-acetylide chromophore. The glasses doped with lower concentrations of AuNPs (2-5 μm average distance) and 50 × 10−3 m in chromophore, show a marked improvement in nonlinear absorption, with no or only small improvement for the more highly AuNP doped glasses. This study shows the importance of excitation wavelength and nanoparticle concentration for composite systems employing AuNPs to improve two-photon absorption of chromophores. [ABSTRACT FROM AUTHOR]

    sted, utgiver, år, opplag, sider
    Weinheim: , 2016. s. 10
    Emneord
    hybrid material, nonlinear absorption, nonlinear optics, plasmon, sol-gel
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-135513 (URN)10.1002/adfm.201601646 (DOI)
    Tilgjengelig fra: 2017-03-16 Laget: 2017-03-16 Sist oppdatert: 2019-04-29bibliografisk kontrollert
    3. Efficient reverse saturable absorption of sol-gel hybrid plasmonic glasses
    Åpne denne publikasjonen i ny fane eller vindu >>Efficient reverse saturable absorption of sol-gel hybrid plasmonic glasses
    Vise andre…
    2017 (engelsk)Inngår i: Optical materials (Amsterdam), ISSN 0925-3467, E-ISSN 1873-1252, Vol. 69, s. 134-140Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    Monolithic silica sol-gel glasses doped with platinum(II) acetylide complexes possessing respectively four or six phenylacetylene units (PE2-CH2OH and PE3-CH2OH) in combination with various concentrations of spherical and bipyramidal gold nanoparticles (AuNPs) known to enhance non-linear optical absorption, were prepared and polished to high optical quality. The non-linear absorption of the glasses was measured and compared to glasses doped solely with AuNPs, a platinum(II) acetylide with shorter delocalized structure, or combinations of both. At 532 nm excitation wavelength the chromophore inhibited the non-linear scattering previously found for glasses only doped with AuNPs. The measured non-linear absorption was attributed to reverse saturable absorption from the chromophore, as previously reported for PE2-CH2OH/AuNP glasses. At 600 nm strong nonlinear absorption was observed for the PE3-CH2OH/AuNPs glasses, also attributed to reverse saturable absorption. But contrary to previous findings for PE2-CH2OH/AuNPs, no distinct enhancement of the non-linear absorption for PE3-CH2OH/AuNPs was observed. A numerical population model for PE3-CH2OH was used to give a qualitative explanation of this difference. A stronger linear absorption in PE3-CH2OH would cause the highly absorbing triplet state to populate quicker during the leading edge of the laser pulse and this would in turn reduce the influence from two-photon absorption enhancement from AuNPs.

    sted, utgiver, år, opplag, sider
    Amsterdam: Elsevier, 2017
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-138093 (URN)10.1016/j.optmat.2017.04.024 (DOI)000404305200018 ()
    Merknad

    Funding agencies: French CNRS; ENS Lyon; UCBL; Swedish Armed Forces

    Tilgjengelig fra: 2017-06-08 Laget: 2017-06-08 Sist oppdatert: 2019-04-29bibliografisk kontrollert
  • 159.
    Magnusson, Roger
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan.
    Mueller matrix ellipsometry studies of nanostructured materials2014Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Materials can be tailored on the nano-scale to show properties that cannot be found in bulk materials. Often these properties reveal themselves when electromagnetic radiation, e.g. light, interacts with the material. Numerous examples of such types of materials are found in nature. There are for example many insects and birds with exoskeletons or feathers that reflect light in special ways. Of special interest in this work is the scarab beetle Cetonia aurata which has served as inspiration to develop advanced nanostructures due to its ability to turn unpolarized light into almost completely circularly polarized light. The objectives of this thesis are to design and characterize bioinspired nanostructures and to develop optical methodology for their analysis.

    Mueller-matrix ellipsometry has been used to extract optical and structural properties of nanostructured materials. Mueller-matrix ellipsometry is an excellent tool for studying the interaction between nanostructures and light. It is a non-destructive method and provides a complete description of the polarizing properties of a sample and allows for determination of structural parameters.

    Three types of nanostructures have been studied. The rst is an array of carbon nanobers grown on a conducting substrate. Detailed information on physical symmetries and band structure of the material were determined. Furthermore, changes in its optical properties when the individual nanobers were electromechanically bent to alter the periodicity of the photonic crystal were studied. The second type of nanostructure studied is bioinspired lms with nanospirals of InxAl1–xN which reflect light with a high degree of circular polarization in a narrow spectral band. These nanostructures were grown under controlled conditions to form columnar structures with an internally graded refractive index responsible for the ability to reflect circularly polarized light. Finally, angle-dependent Mueller matrices were recorded of natural nanostructures in C. aurata with the objective to refine the methodology for structural analysis. A Cloude sum decomposition was applied and a more stable regression-based decomposition was developed for deepened analysis of these depolarizing Mueller matrices. It was found that reflection at near-normal incidence from C. aurata can be described as a sum reflection o a mirror and a left-handed circular polarizer. At oblique incidence the description becomes more complex and involves additional optical components.

    Delarbeid
    1. Chirality-induced polarization effects in the cuticle of scarab beetles: 100 years after Michelson
    Åpne denne publikasjonen i ny fane eller vindu >>Chirality-induced polarization effects in the cuticle of scarab beetles: 100 years after Michelson
    2012 (engelsk)Inngår i: Philosophical Magazine, ISSN 1478-6435, E-ISSN 1478-6443, Vol. 92, nr 12, s. 1583-1599Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    One hundred years ago Michelson discovered circular polarization in reflection from beetles. Today a novel Mueller-matrix ellipsometry setup allows unprecedented detailed characterization of the beetles polarization properties. A formalism based on elliptical polarization for description of reflection from scarab beetles is here proposed and examples are given on four beetles of different character: Coptomia laevis - a simple dielectric mirror; Cetonia aurata - a left-hand narrow- band elliptical polarizer; Anoplognathus aureus - a broad-band elliptical polarizer; and Chrysina argenteola - a left-hand polarizer for visible light at small angles, whereas for larger angles, red reflected light is right-handed polarized. We confirm the conclusion of previous studies which showed that a detailed quantification of ellipticity and degree of polarization of cuticle reflection can be performed instead of only determining whether reflections are circularly polarized or not. We additionally investigate reflection as a function of incidence angle. This provides much richer information for understanding the behaviour of beetles and for structural analysis.

    sted, utgiver, år, opplag, sider
    Taylor and Francis: STM, Behavioural Science and Public Health Titles / Taylor and Francis, 2012
    Emneord
    scarab beetles, Mueller-matrix ellipsometry, elliptical polarization, structural colours
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-77876 (URN)10.1080/14786435.2011.648228 (DOI)000303578700008 ()
    Merknad
    Funding Agencies|Knut and Alice Wallenberg foundation||Swedish Research Council||Tilgjengelig fra: 2012-05-31 Laget: 2012-05-31 Sist oppdatert: 2017-12-07
    2. Chiral nanostructures producing near circular polarization
    Åpne denne publikasjonen i ny fane eller vindu >>Chiral nanostructures producing near circular polarization
    Vise andre…
    2014 (engelsk)Inngår i: Optical Materials Express, ISSN 2159-3930, E-ISSN 2159-3930, Vol. 4, nr 7, s. 1389-1403Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    Optical properties of chiral nanostructured films made of Al1-xInxN using a new growth mechanism - curved-lattice epitaxial growth - are reported. Using this technique, chiral films with right- and left-handed nanospirals were produced. The chiral properties of the films, originating mainly from an internal anisotropy and to a lesser extent from the external helical shape of the nanospirals, give rise to selective reflection of circular polarization which makes them useful as narrow-band near-circular polarization reflectors. The chiral nanostructured films reflect light with high degree of circular polarization in the ultraviolet part of the spectrum with left- and right-handedness depending on the handedness of the nanostructures in the films.

    sted, utgiver, år, opplag, sider
    Optical Society of America, 2014
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-109241 (URN)10.1364/OME.4.001389 (DOI)000338875100013 ()
    Tilgjengelig fra: 2014-08-12 Laget: 2014-08-11 Sist oppdatert: 2018-03-08bibliografisk kontrollert
    3. Optical Mueller Matrix Modeling of Chiral AlxIn1-xN Nanospirals
    Åpne denne publikasjonen i ny fane eller vindu >>Optical Mueller Matrix Modeling of Chiral AlxIn1-xN Nanospirals
    Vise andre…
    2014 (engelsk)Inngår i: Thin Solid Films, ISSN 0040-6090, E-ISSN 1879-2731, Vol. 571, s. 447-452Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    Metamaterials in the form of chiral nanostructures have shown great potential for applications such as chemical and biochemical sensors and broadband or wavelength tunable circular polarizers. Here we demonstrate a method to produce tailored transparent chiral nanostructures with the wide-bandgap semiconductor AlxIn1 − xN. A series of anisotropic and transparent films of AlxIn1 − xN were produced using curved-lattice epitaxial growth on metallic buffer layers. By controlling the sample orientation during dual magnetron sputter deposition, nanospirals with right-handed or left-handed chirality were produced. Using a dual rotating compensator ellipsometer in reflection mode, the full Mueller matrix was measured in the spectral range 245–1700 nm at multiple angles of incidence. The samples were rotated one full turn around their normal during measurements to provide a complete description of the polarization properties in all directions. For certain wavelengths, unpolarized light reflected off these films becomes highly polarized with a polarization state close to circular. Nanostructured films with right- and left-handed chirality produce reflections with right- and left-handed near-circularly polarized light, respectively. A model with a biaxial layer in which the optical axes are rotated from bottom to top was fitted to the Mueller-matrix data. Hence we can perform non-destructive structural analysis of the complex thin layers and confirm the tailored structure. In addition, the refractive index, modeled with a biaxial Cauchy dispersion model, is obtained for the AlxIn1 − xN films.

    sted, utgiver, år, opplag, sider
    Elsevier, 2014
    Emneord
    Chiral nanostructures; Mueller matrix spectroscopic ellipsometry; Anisotropy; Optical modeling;High degree of circular polarization
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-106421 (URN)10.1016/j.tsf.2014.02.015 (DOI)000346055200020 ()
    Tilgjengelig fra: 2014-05-07 Laget: 2014-05-07 Sist oppdatert: 2018-03-08
    4. Optical properties of carbon nanofiber photonic crystals
    Åpne denne publikasjonen i ny fane eller vindu >>Optical properties of carbon nanofiber photonic crystals
    Vise andre…
    2010 (engelsk)Inngår i: NANOTECHNOLOGY, ISSN 0957-4484, Vol. 21, nr 46, s. 465203-Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    Carbon nanofibers (CNFs) are used as components of planar photonic crystals. Square and rectangular lattices and random patterns of vertically aligned CNFs were fabricated and their properties studied using ellipsometry. We show that detailed information such as symmetry directions and the band structure of these novel materials can be extracted from considerations of the polarization state in the specular beam. The refractive index of the individual nanofibers was found to be n(CNF) = 4.1.

    sted, utgiver, år, opplag, sider
    Institute of Physics; 1999, 2010
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-61309 (URN)10.1088/0957-4484/21/46/465203 (DOI)000283491000003 ()
    Merknad

    Original Publication: R Rehammar, Roger Magnusson, A I Fernandez-Dominguez, Hans Arwin, J M Kinaret, S A Maier and E E B Campbell, Optical properties of carbon nanofiber photonic crystals, 2010, NANOTECHNOLOGY, (21), 46, 465203. http://dx.doi.org/10.1088/0957-4484/21/46/465203 Copyright: Institute of Physics; 1999 http://www.iop.org/

    Tilgjengelig fra: 2010-11-12 Laget: 2010-11-12 Sist oppdatert: 2015-09-22
    5. Electromechanically Tunable Carbon Nanofiber Photonic Crystal
    Åpne denne publikasjonen i ny fane eller vindu >>Electromechanically Tunable Carbon Nanofiber Photonic Crystal
    Vise andre…
    2013 (engelsk)Inngår i: Nano letters (Print), ISSN 1530-6984, E-ISSN 1530-6992, Vol. 13, nr 2, s. 397-401Artikkel i tidsskrift, Letter (Fagfellevurdert) Published
    Abstract [en]

    We demonstrate an electrically tunable 2D photonic crystal array constructed from vertically alignedcarbon nanofibers. The nanofibers are actuated by applying a voltage between adjacent carbon nanofiberpairs grown directly on metal electrodes, thus dynamically changing the form factor of the photoniccrystal lattice. The change in optical properties is characterised using optical diffraction andellipsometry. The experimental results are shown to be in agreement with theoretical predictions andprovide a proof-of-principle for rapidly switchable photonic crystals operating in the visible that can befabricated using standard nanolithography techniques combined with plasma CVD growth of thenanofibers.

    sted, utgiver, år, opplag, sider
    AMER CHEMICAL SOC, 2013
    Emneord
    carbon nanofiber, nanoelectromechanics, diffraction, ellipsometry, form factor, tunable photonic crystal
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-86730 (URN)10.1021/nl3035527 (DOI)000315079500012 ()
    Tilgjengelig fra: 2012-12-31 Laget: 2012-12-31 Sist oppdatert: 2017-12-06
    6. Sum decomposition of Mueller-matrix images and spectra of beetle cuticles
    Åpne denne publikasjonen i ny fane eller vindu >>Sum decomposition of Mueller-matrix images and spectra of beetle cuticles
    Vise andre…
    2015 (engelsk)Inngår i: Optics Express, ISSN 1094-4087, E-ISSN 1094-4087, Vol. 23, nr 3, s. 1951-1966Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    Spectral Mueller matrices measured at multiple angles of incidence as well as Mueller matrix images are recorded on the exoskeletons (cuticles) of the scarab beetles Cetonia aurata and Chrysina argenteola. Cetonia aurata is green whereas Chrysina argenteola is gold-colored. When illuminated with natural (unpolarized) light, both species reflect left-handed and near-circularly polarized light originating from helicoidal structures in their cuticles. These structures are referred to as circular Bragg reflectors. For both species the Mueller matrices are found to be nondiagonal depolarizers. The matrices are Cloude decomposed to a sum of non-depolarizing matrices and it is found that the cuticle optical response, in a first approximation can be described as a sum of Mueller matrices from an ideal mirror and an ideal circular polarizer with relative weights determined by the eigenvalues of the covariance matrices of the measured Mueller matrices. The spectral and image decompositions are consistent with each other. A regression-based decomposition of the spectral and image Mueller matrices is also presented whereby the basic optical components are assumed to be a mirror and a circular polarizer as suggested by the Cloude decomposition. The advantage with a regression decomposition compared to a Cloude decomposition is its better stability as the matrices in the decomposition are determined a priori. The origin of the depolarizing features are discussed but from present data it is not possible to conclude whether the two major components, the mirror and the circular polarizer are laterally separated in domains in the cuticle or if the depolarization originates from the intrinsic properties of the helicoidal structure.

    sted, utgiver, år, opplag, sider
    Optical Society of America, 2015
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-111944 (URN)10.1364/OE.23.001951 (DOI)000349688800025 ()
    Tilgjengelig fra: 2014-11-11 Laget: 2014-11-11 Sist oppdatert: 2017-12-05bibliografisk kontrollert
    7. Sum regression decomposition of spectral and angle-resolved Mueller-matrices from biological reflectors
    Åpne denne publikasjonen i ny fane eller vindu >>Sum regression decomposition of spectral and angle-resolved Mueller-matrices from biological reflectors
    Vise andre…
    2016 (engelsk)Inngår i: Applied Optics, ISSN 1559-128X, E-ISSN 2155-3165, Vol. 55, nr 15, s. 4060-4065Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    In this report we present studies on beetles of the Scarabaeidae family. The selected beetles show brilliant colors and in addition interesting polarization features. Mueller matrices of such beetles are of large interest to explore for biomimetics and for the understanding of the biological relevance of the observed polarization phenomena. Several species of the Scarabaeidae family have been studied by Hodgkinson, Goldstein  and our group to mention some. Ellipticity, degree of polarization and other derived parameters have been reported and Arwin et al. also did optical modeling to determine structural parameters of the scutellum part of the exoskeleton of Cetonia aurata. Mueller matrices are very rich in information about the sample properties and can also be analyzed by addressing depolarization. Cloude showed that a depolarizing Mueller matrix can be represented by a sum of up to four non-depolarizing Mueller matrices weighted by the eigenvalues of the covariance matrix of the Mueller matrix. These eigenvalues are all positive for a physically realizable Mueller matrix and this, so called sum decomposition can be used to filter matrices and obtain a measure of experimental fidelity. The result of the decomposition can also be used to describe a Mueller matrix as a set of basic optical elements having direct physical meaning, such as polarizers and retarders. Pioneering work on decomposition of Mueller-matrix images, including studies of beetles, was performed by Ossikovski et al. We have also previously demonstrated this with Cloude as well as regression decomposition of Mueller matrix spectra and images measured at near-normal incidence on C. aurata. Using Cloude decomposition we found that the experimentally determined Mueller matrix of C. aurata decomposes into a set of a mirror and a circular polarizer. Those results were then the basis for a more stable regression decomposition where the result was confirmed.

    sted, utgiver, år, opplag, sider
    Optical Society of America, 2016
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-111946 (URN)10.1364/AO.55.004060 (DOI)000376382300022 ()
    Merknad

    Funding agencies:  Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linkoping University (Faculty Grant SFO Mat LiU) [2009 00971]; Vetenskapsradet (VR) [621-2011-4283]; Knut och Alice Wallenbergs Stiftelse [2004.0233]; Carl Tryggers

    Vid tiden för disputation förelåg publikationen endast som manuskript

    Tilgjengelig fra: 2014-11-11 Laget: 2014-11-11 Sist oppdatert: 2017-12-05bibliografisk kontrollert
  • 160.
    Magnusson, Roger
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska fakulteten.
    Arwin, Hans
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan.
    Garcia-Caure, Enric
    LPICM, CNRS, Ecole Polytechnique, Université Paris–Saclay, Palaiseau, France.
    Järrendahl, Kenneth
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska fakulteten.
    Ossikovski, Razvigor
    LPICM, CNRS, Ecole Polytechnique, Université Paris–Saclay, Palaiseau, France.
    Sum regression decomposition of spectral and angle-resolved Mueller-matrices from biological reflectors2016Inngår i: Applied Optics, ISSN 1559-128X, E-ISSN 2155-3165, Vol. 55, nr 15, s. 4060-4065Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In this report we present studies on beetles of the Scarabaeidae family. The selected beetles show brilliant colors and in addition interesting polarization features. Mueller matrices of such beetles are of large interest to explore for biomimetics and for the understanding of the biological relevance of the observed polarization phenomena. Several species of the Scarabaeidae family have been studied by Hodgkinson, Goldstein  and our group to mention some. Ellipticity, degree of polarization and other derived parameters have been reported and Arwin et al. also did optical modeling to determine structural parameters of the scutellum part of the exoskeleton of Cetonia aurata. Mueller matrices are very rich in information about the sample properties and can also be analyzed by addressing depolarization. Cloude showed that a depolarizing Mueller matrix can be represented by a sum of up to four non-depolarizing Mueller matrices weighted by the eigenvalues of the covariance matrix of the Mueller matrix. These eigenvalues are all positive for a physically realizable Mueller matrix and this, so called sum decomposition can be used to filter matrices and obtain a measure of experimental fidelity. The result of the decomposition can also be used to describe a Mueller matrix as a set of basic optical elements having direct physical meaning, such as polarizers and retarders. Pioneering work on decomposition of Mueller-matrix images, including studies of beetles, was performed by Ossikovski et al. We have also previously demonstrated this with Cloude as well as regression decomposition of Mueller matrix spectra and images measured at near-normal incidence on C. aurata. Using Cloude decomposition we found that the experimentally determined Mueller matrix of C. aurata decomposes into a set of a mirror and a circular polarizer. Those results were then the basis for a more stable regression decomposition where the result was confirmed.

  • 161.
    Magnusson, Roger
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska fakulteten.
    Birch, Jens
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Hsiao, Ching-Lien
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Sandström, Per
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Arwin, Hans
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska fakulteten.
    Järrendahl, Kenneth
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska fakulteten.
    InxAl1-xN chiral nanorods mimicking the polarization features of scarab beetles2015Inngår i: SPIE Proceedings Vol. 942: Bioinspiration, Biomimetics, and Bioreplication 2015 / [ed] Akhlesh Lakhtakia, Mato Knez, Raúl Martín-Palma, SPIE - International Society for Optical Engineering, 2015, Vol. 9429, s. 94290A-1-94290A-8Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The scarab beetle Cetonia aurata is known to reflect light with brilliant colors and a high degree of circular polarization. Both color and polarization effects originate from the beetles exoskeleton and have been attributed to a Bragg reflection of the incident light due to a twisted laminar structure. Our strategy for mimicking the optical properties of the Cetonia aurata was therefore to design and fabricate transparent, chiral films. A series of films with tailored transparent structures of helicoidal InxAl1-xN nanorods were grown on sapphire substrates using UHV magnetron sputtering. The value of x is tailored to gradually decrease from one side to the other in each nanorod normal to its growth direction. This introduces an in-plane anisotropy with different refractive indices in the direction of the gradient and perpendicular to it. By rotating the sample during film growth the in-plane optical axis will be rotated from bottom to top and thereby creating a chiral film. Based on Muellermatrix ellipsometry, optical modeling has been done suggesting that both the exoskeleton of Cetonia aurata and our artificial material can be modeled by an anisotropic film made up of a stack of thin layers, each one with its in-plane optical axis slightly rotated with respect to the previous layer. Simulations based on the optical modeling were used to investigate how pitch and thickness of the film together with the optical properties of the constitutive materials affects the width and spectral position of the Bragg reflection band.

  • 162.
    Magnusson, Roger
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan.
    Birch, Jens
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Sandström, Per
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Hsiao, Ching-Lien
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Arwin, Hans
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan.
    Järrendahl, Kenneth
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan.
    Optical Mueller Matrix Modeling of Chiral AlxIn1-xN Nanospirals2014Inngår i: Thin Solid Films, ISSN 0040-6090, E-ISSN 1879-2731, Vol. 571, s. 447-452Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Metamaterials in the form of chiral nanostructures have shown great potential for applications such as chemical and biochemical sensors and broadband or wavelength tunable circular polarizers. Here we demonstrate a method to produce tailored transparent chiral nanostructures with the wide-bandgap semiconductor AlxIn1 − xN. A series of anisotropic and transparent films of AlxIn1 − xN were produced using curved-lattice epitaxial growth on metallic buffer layers. By controlling the sample orientation during dual magnetron sputter deposition, nanospirals with right-handed or left-handed chirality were produced. Using a dual rotating compensator ellipsometer in reflection mode, the full Mueller matrix was measured in the spectral range 245–1700 nm at multiple angles of incidence. The samples were rotated one full turn around their normal during measurements to provide a complete description of the polarization properties in all directions. For certain wavelengths, unpolarized light reflected off these films becomes highly polarized with a polarization state close to circular. Nanostructured films with right- and left-handed chirality produce reflections with right- and left-handed near-circularly polarized light, respectively. A model with a biaxial layer in which the optical axes are rotated from bottom to top was fitted to the Mueller-matrix data. Hence we can perform non-destructive structural analysis of the complex thin layers and confirm the tailored structure. In addition, the refractive index, modeled with a biaxial Cauchy dispersion model, is obtained for the AlxIn1 − xN films.

  • 163.
    Magnusson, Roger
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan.
    Hsiao, Ching-Lien
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Birch, Jens
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Arwin, Hans
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan.
    Järrendahl, Kenneth
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan.
    Chiral nanostructures producing near circular polarization2014Inngår i: Optical Materials Express, ISSN 2159-3930, E-ISSN 2159-3930, Vol. 4, nr 7, s. 1389-1403Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Optical properties of chiral nanostructured films made of Al1-xInxN using a new growth mechanism - curved-lattice epitaxial growth - are reported. Using this technique, chiral films with right- and left-handed nanospirals were produced. The chiral properties of the films, originating mainly from an internal anisotropy and to a lesser extent from the external helical shape of the nanospirals, give rise to selective reflection of circular polarization which makes them useful as narrow-band near-circular polarization reflectors. The chiral nanostructured films reflect light with high degree of circular polarization in the ultraviolet part of the spectrum with left- and right-handedness depending on the handedness of the nanostructures in the films.

  • 164.
    Magnusson, Roger
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska fakulteten.
    Ossikovski, Razvigor
    LPICM, CNRS, Ecole Polytechnique, Université Paris - Saclay, Palaiseau, France.
    Garcia-caurel, Enric
    LPICM, CNRS, Ecole Polytechnique, Université Paris - Saclay, Palaiseau, France.
    Järrendahl, Kenneth
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska fakulteten.
    Arwin, Hans
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska fakulteten.
    Decomposition of angle resolved spectroscopic Mueller matrices from Scarabaeidae beetles2015Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    We use angle-dependent Mueller-matrix spectroscopic ellipsometry (MMSE) to determine Mueller matrices of Scarabaeidae beetles which show fascinating reflection properties due to structural phenomena in the exocuticle which are often depolarizing. It has been shown by Cloude [1] that a depolarizing matrix can be decomposed into a sum of up to four non-depolarizing matrices according to M= aM­­1+bM2+cM3+dM4, where a, b, c and d are eigenvalues of the covariance matrix of M. Using the same eigenvalues the matrices Mi can be calculated. This method provides the full solution to the decomposition with both the non-depolarizing matrices and the weight of each of them in the sum.

    An alternative to Cloude decomposition is regression decomposition. Here any Mueller matrix can be decomposed into a set of matrices Mi which are specified beforehand. Whereas in Cloude decomposition the only constraint on the matrices is that they are physically realizable non-depolarizing Mueller matrices, we can now limit the constraint and only use Mueller matrices representing pure optical devices having direct physical meaning, such as polarizers, retarders, etc. This leaves a, b, c, d as fit parameters to minimize the Frobenius norm Mexp -Mreg where Mexp is the experimentally determined Mueller matrix to be decomposed and Mreg is the sum of all Mi. Depending on Mexp an appropriate choice of Mreg matrices has to be made and different values of a, b, c and d are obtained through regression analysis.

    We have previously shown that regression decomposition can be used to show that the Mueller matrix of Cetonia aurata can be decomposed into a sum of a circular polarizer and a mirror [2]. Here we expand the analysis to include angle-resolved spectral Mueller matrices, and also include more species of Scarabaeidae beetles.

    One effect of the decomposition is that when depolarization is caused by an inhomogeneous sample with regions of different optical properties the Mueller matrices of the different regions can be retrieved under certain conditions. Regression decomposition also has potential to be a classification tool for biological samples where a set of standard matrices are used in the decomposition and the parameters a, b, c, d are used to quantify the polarizing properties of the sample.

    [1] Cloude S.R. 1989. Conditions for the physical realisability of matrix operators in polarimetry. Proc. SPIE 1166, Polarization Considerations for Optical Systems II, pp. 177-185

    [2] Arwin H, Magnusson R, Garcia-Caurel E, Fallet C, Järrendahl K, De Martino A, Ossikovski R, 2015. Sum decomposition of Mueller-matrix images and spectra of beetle cuticles. Opt. Express, vol. 23, no. 3, pp. 1951–1966

  • 165.
    Magnusson, Roger
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan.
    Rehammar, Robert
    Göteborg University.
    Arwin, Hans
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan.
    Lattices of Freestanding Carbon Nanofibres Characterized by Spectroscopic Ellipsometry2009Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    Photonic crystals with lattice constant in the visible range of light can be fabricated using freestanding carbon nanofibres. These types of structures are optically complicated, with geometric effects both from the lattice and from individual scatterers. In this report, results from pilot studies of the optical properties of such samples are presented.

    Ellipsometric measurements on samples with vertically aligned arrays of free-standing carbon nanofibres with lengths up to 1600 nm are presented. The carbon nanofibres were grown on silicon wafers with a 70 nm layer of titanium and a 15 nm layer of titanium nitride using plasma-CVD with nickel as catalyst. Electron beam lithography was used to create the nanofibre lattice. Samples with varying periodicity and length of the carbon fibers, i.e. film thickness, were investigated.

    In this pilot study measurements were performed with a dual rotating compensator ellipsometer in the spectral range 245-1700 nm. The instrument provides the full Mueller matrix of the sample and measurements were performed at multiple angles of incidence and different sample orientations.

    The samples show no difference in the optical response when rotated 90°, but at other orientations changes in the spectrum are observed below a wavelength of approximately 1000 nm. The analysis of the ellipsometric data is presented and different modeling approaches are discussed.

  • 166.
    Mendoza, Arturo
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan. Cinvestav-IPN, Unidad Querétaro, Mexico.
    Arreola-Jardón, Gerardo
    Cinvestav-IPN, Unidad Querétaro, Mexico.
    Karlsson, Linda
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Persson, Per
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Jiménez-Sandoval, Sergio
    Cinvestav-IPN, Unidad Querétaro, Mexico.
    Optical properties of CuCdTeO thin films sputtered from CdTe-CuO composite targets2014Inngår i: Thin Solid Films, ISSN 0040-6090, E-ISSN 1879-2731, Vol. 571, s. 706-711Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The effective complex dielectric function (ε) of Cu and O containing CdTe thin films is reported in the spectral range of 0.05 to 6 eV. The films were fabricated by rf sputtering from targets comprised by a mixture of CdTe and CuO powders with nominal Cu and O concentrations in the range of 2–10 at.%. Low concentration levels improved the crystalline quality of the films. Spectroscopic ellipsometry and transmittance measurements were used to determine ε. The critical point energies E1, E11, and E2 of CdTe are red-shifted with the incorporation of Cu and O. Also, an absorption band is developed in the infrared range which is associated with a mixture of CdTe and low resistivity phases Cu2 − xTe according to an effective medium analysis. The elemental distribution of the films was mapped by energy dispersive X-ray spectroscopy using scanning transmission electron microscopy.

  • 167.
    Mendoza, Arturo
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan. Cinvestav-Querétaro, Mexico.
    Muñoz-Pineda, Eloy
    Cinvestav-Querétaro, Mexico.
    Järrendahl, Kenneth
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan.
    Arwin, Hans
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan.
    Evidence for a dispersion relation of optical modes in the cuticle of the scarab beetle Cotinis mutabilis2014Inngår i: Optical Materials Express, ISSN 2159-3930, E-ISSN 2159-3930, Vol. 4, nr 12, s. 2484-2496Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Variable angle Mueller matrix spectroscopic ellipsometry is used to study the properties of light reflected from the exoskeleton (cuticle) of the scarab beetle Cotinis mutabilis. For unpolarized incident light, the ellipticity and degree of polarization of the reflected light reveal a lefthanded helical structure in the beetle cuticle. Analysis of the spectral position of the maxima and minima in the interference oscillations of the Mueller-matrix elements provides evidence for a dispersion relation similar to that of optical modes in chiral nematic liquid crystals calculated within a two-wave approximation. Additionally, a structural model for the cuticle of C. mutabilis is derived from the properties of the optical modes for nonattenuated propagation or selective reflection.

  • 168.
    Mendoza-Galvan, A.
    et al.
    Cinvestav-IPN, Unidad Querétaro, Querétaro, Mexico.
    Järrendahl, Kenneth
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan.
    Dmitriev, A.
    Department of Applied Physics, Chalmers University of Technology, Göteborg.
    Pakizeh, T.
    Faculty of Electrical and Computer Engineering, K. N. Toosi University of Technology, Tehran, Iran.
    Käll, M.
    Department of Applied Physics, Chalmers University of Technology, Göteborg.
    Arwin, Hans
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan.
    Optical response of supported gold nanodisks2011Inngår i: Optics Express, ISSN 1094-4087, E-ISSN 1094-4087, Vol. 19, nr 13, s. 12093-12107Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    It is shown that the ellipsometric spectra of short range ordered planar arrays of gold nanodisks supported on glass substrates can be described by modeling the nanostructured arrays as uniaxial homogeneous layers with dielectric functions of the Lorentz type. However, appreciable deviations from experimental data are observed in calculated spectra of irradiance measurements. A qualitative and quantitative description of all measured spectra is obtained with a uniaxial effective medium dielectric function in which the nanodisks are modeled as oblate spheroids. Dynamic depolarization factors in the long-wavelength approximation and interaction with the substrate are considered. Similar results are obtained calculating the optical spectra using the island-film theory. Nevertheless, a small in-plane anisotropy and quadrupolar coupling effects reveal a very complex optical response of the nanostructured arrays.

  • 169.
    Mendoza-Galvan, A.
    et al.
    CINVESTAV, Mexico.
    Munoz-Pineda, E.
    CINVESTAV, Mexico.
    Järrendahl, Kenneth
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska fakulteten.
    Arwin, Hans
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska fakulteten.
    Birefringence of nanocrystalline chitin films studied by Mueller-matrix spectroscopic ellipsometry2016Inngår i: Optical Materials Express, ISSN 2159-3930, E-ISSN 2159-3930, Vol. 6, nr 2, s. 671-681Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Birefringent chitin films were prepared by a dipping technique from aqueous suspensions of chitin nanocrystals in a nematic liquid crystal phase. In the films, chitin nanocrystals are preferentially oriented along the withdrawal direction. Normal incidence transmission Mueller-matrix (M) spectroscopic ellipsometry measurements as a function of sample rotation were used to investigate the optical birefringence in the spectral range 0.73 to 5 eV. Analysis of eigenvalues and depolarization data reveal that the Mueller matrix corresponds to a pure retarder for photon energies below 4 eV and is depolarizing in the range 4 to 5 eV. By modeling the chitin film as a slab with in-plane anisotropy the birefringence was determined. The determination of birefringence was extended to include the range of 4 to 5 eV by a differential decomposition of M. (C) 2016 Optical Society of America

  • 170.
    Mendoza-Galvan, Arturo
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska fakulteten.
    Järrendahl, Kenneth
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska fakulteten.
    Arwin, Hans
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan.
    Huang, Yi-Fan
    National Taipei University of Technology.
    Chen, Li-Chyong
    National Taipei University of Technology.
    Chen, Kuei-Hsien
    National Taiwan University.
    Spectroscopic ellipsometry analysis of silicon nanotips obtained by electron cyclotron resonance plasma etching2009Inngår i: APPLIED OPTICS, ISSN 0003-6935, Vol. 48, nr 26, s. 4996-5004Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Silicon nanotips fabricated by electron cyclotron resonance plasma etching of silicon wafers are studied by spectroscopic ellipsometry. The structure of the nanotips is composed of columns 100-140 nm wide and spaced by about 200 nm. Ellipsometry data covering a wide spectral range from the midinfrared to the visible are described by modeling the nanotip layer as a graded uniaxial film using the Bruggeman effective medium approximation. The ellipsometry data in the infrared range reveal two absorption bands at 754 and 955 cm(-1), which cannot be resolved with transmittance measurements. These bands indicate that the etching process is accompanied with formation of carbonaceous SiC and CHn species that largely modify the composition of the original crystalline silicon material affecting the optical response of the nanotips. (C) 2009 Optical Society of America

  • 171.
    Mendoza-Galvan, Arturo
    et al.
    Cinvestav-Querétaro, Libramiento Norponiente.
    Rybka, M
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Järrendahl, Kenneth
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Arwin, Hans
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan.
    Magnuson, Martin
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Hultman, Lars
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Barsoum, Michel
    Drexel University.
    Spectroscopic ellipsometry study on the dielectric function of bulk Ti2AlN,Ti2AlC, Nb2AlC, (Ti0.5,Nb0.5)2AlC, and Ti3GeC2 MAX-phases2011Inngår i: Journal of Applied Physics, ISSN 0021-8979, E-ISSN 1089-7550, Vol. 109, s. 013530-Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The averaged complex dielectric function =2+ /3 of polycrystalline Ti2AlN, Ti2AlC,Nb2AlC, Ti0.5,Nb0.52AlC, and Ti3GeC2 was determined by spectroscopic ellipsometry coveringthe mid infrared to the ultraviolet spectral range. The dielectric functions and correspond tothe perpendicular and parallel dielectric tensor components relative to the crystallographic c-axis ofthese hexagonal compounds. The optical response is represented by a dispersion model with Drude–Lorentz and critical point contributions. In the low energy range the electrical resistivity is obtainedfrom the Drude term and ranges from 0.48 m for Ti3GeC2 to 1.59 m for Ti0.5,Nb0.52AlC.Furthermore, several compositional dependent interband electronic transitions can be identified. Forthe most important ones, Im shows maxima at: 0.78, 1.23, 2.04, 2.48, and 3.78 eV for Ti2AlN;0.38, 1.8, 2.6, and 3.64 eV for Ti2AlC; 0.3, 0.92, and 2.8 eV in Nb2AlC; 0.45, 0.98, and 2.58 eV inTi0.5,Nb0.52AlC; and 0.8, 1.85, 2.25, and 3.02 eV in Ti3GeC2.

  • 172.
    Mendoza-Galvan, Arturo
    et al.
    Cinvestav-Queretaro, Mexico.
    Rybka, Marcin
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan.
    Järrendahl, Kenneth
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan.
    Arwin, Hans
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan.
    Magnuson, Martin
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Hultman, Lars
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Barsoum, Michel
    Drexel University.
    Spectroscopic Ellipsometry of Bulk MAX-phases2009Inngår i: Proceedings of the AVS 56th International Symposium & Exhibition, 2009, 2009Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    MAX-phases are compounds with the chemical formula Mn+1AXn where M is a transition metal, A is an element from column 13 to 16 in the periodic system and X represents C or N and n = 1, 2 or 3. These materials are potentially technologically important as they show unique refractory and other physical properties due to the combination of metals and ceramics. From a fundamental point of view the band structure of these materials are of interest and optical reference data are important to determine. Herein we report, for the first time, on the optical properties of NbTiAlC, Nb2AlC, TiSC2, Cr2GeC, TiGeC2, Ti2AlC, and Ti2AlN by spectroscopic ellipsometry in the 0.03 to 6.0 eV spectral range. The ellipsometric data in the infrared range show features corresponding to Fano modes indicating the presence of a thin oxide layer a few nm thick. The optical response of these MAX-phases is represented by a Drude-Lorentz model. Thus, in the low energy range the electrical conductivity through the Drude term is evaluated and two or three interband electronic transitions which are compositional dependent can be identified at photon energies in the visible-ultraviolet range 1.0-6.0 eV.

  • 173.
    Mendoza-Galván, Arturo
    et al.
    Cinvestav-Querétaro, Mexico.
    Järrendahl, Kenneth
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan.
    Arwin, Hans
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan.
    Huang, I.F.
    National Taipei University of Technology.
    Chen, K.H
    National Taiwan University.
    Spectroscopic ellipsometry analysis of silicon nanotips obtained by electron cyclotron resonance plasma etching2009Konferansepaper (Annet vitenskapelig)
  • 174.
    Mendoza-Galván, Arturo
    et al.
    Cinvestav-IPN, Unidad Querétaro, Querétaro, Mexico .
    Järrendahl, Kenneth
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan.
    Dmitriev, Alexander
    Department of Applied Physics, Chalmers University of Technology, Göteborg, Sweden.
    Pakizeh, T.
    Faculty of Electrical and Computer Engineering, K. N. Toosi University of Technology, Tehran, Iran.
    Käll, Mikael
    Department of Applied Physics, Chalmers University of Technology, Göteborg, Sweden.
    Arwin, Hans
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan.
    Fano interference in supported gold nanosandwiches with weakly coupled nanodisks2012Inngår i: Optics Express, ISSN 1094-4087, E-ISSN 1094-4087, Vol. 20, nr 28, s. 29646-29658Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We studied the far-field optical response of supported gold-silica-gold nanosandwiches using spectroscopic ellipsometry, reflectance and transmittance measurements. Although transmittance data clearly shows that the gold nanodisks in the sandwich structure interact very weakly, oblique reflectance spectra of s- and p-polarized light show clearly asymmetric line-shapes of the Fano type. However, all experimental results are very well described by modeling the gold nanodisks as oblate spheroids and by employing a 2 × 2 scattering matrix formulation of the Fresnel coefficients provided by an island film theory. In particular, the Fano asymmetry can be explained in terms of interference between the scattered waves from the decoupled nanodisks in the spectral range limited by their respective plasmon resonances. We also show that the reflectance and ellipsometry spectra can be described by a three-layer system with uniaxial effective dielectric functions.

  • 175.
    Mendoza-Galván, Arturo
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi.
    Muñoz-Pineda, Eloy
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik.
    Ribeiro, S.J.L.
    LaMF—UNESP Instituto de Química, Araraquara, Brazil.
    Vieira Dos Santos, M.
    LaMF—UNESP Instituto de Química, Araraquara, Brazil.
    Järrendahl, Kenneth
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska fakulteten.
    Arwin, Hans
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska fakulteten.
    Mueller matrix spectroscopic ellipsometry study of nanocrystalline cellulose free-standing chiral films2015Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    The astonishing colors exhibited by many birds, insects and other creatures have inspired the development of materials and structures for optical biomimetics. Particularly, aqueous suspensions of cellulose nanocrystals self-assembly in a chiral nematic liquid crystalline phase producing nanocrystalline cellulose (NCC) chiral films after slow evaporation [1] that mimic the left-handed helicoidal arrangement of chitin-protein fibrils found in some beetle cuticles. Owing to the helical structure, left-handed polarized light is selectively reflected from beetle cuticles and NCC chiral films at normal incidence in a spectral band centered at wavelength l0=nL where n is the in-plane average refractive index and L the helix pitch.

    In this work we report the normalized Mueller matrix (M) of NCC free-standing chiral films measured with a dual rotating compensator ellipsometer (J. A. Woollam Co., Inc.) in the wavelength (l) range  250-1000 nm. Measurements performed on NCC films in reflection at angles of incidence (q) between 20 and 75° are shown in the contour map in Fig. 1 and display the same structure as those found in M of beetle cuticles [2]. At q=20° the band of selective reflection of left-handed polarized light (m41=m14<0) is centered at 520 nm. However, NCC chiral films are characterized by a mosaic-like texture as can be observed in the optical microscopy image inserted on the right panel of Fig. 1. The multidomain texture indicates both random helix direction and pitch distribution. Therefore, measurements in different places show selective reflection bands with different spectral characteristics. On the other hand, the transmission of right-handed polarized light (m41=m14>0) is confirmed from measurements at normal incidence, as observed in the right panel of Fig. 1. Other properties of the transmitted light like degree of polarization, ellipticity, and azimuth are determined for incident unpolarized as well as for different polarizations of incident light. Also, circular dichroism and optical rotation of NCC chiral films are evaluated.

    References

    [1] J. A. Kelly et al, Acc. Chem. Res. 47 (2014) 1088−1096.

    [2] E. Muñoz-Pineda et al, Thin Solid Films (2014) http://dx.doi.org/10.1016/j.tsf.2013.11.144

  • 176.
    Muller, Christian
    et al.
    Esfera UAB.
    Bergqvist, Jonas
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska fakulteten.
    Vandewal, Koen
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska fakulteten.
    Tvingstedt, Kristofer
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska högskolan.
    Anselmo, Ana Sofia
    Karlstads University.
    Magnusson, Roger
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik.
    Alonso, M .Isabel
    Esfera UAB.
    Moons, Ellen
    Karlstads University.
    Arwin, Hans
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan.
    Campoy-Quiles, Mariano
    Esfera UAB.
    Inganäs, Olle
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska högskolan.
    Phase behaviour of liquid-crystalline polymer/fullerene organic photovoltaic blends: thermal stability and miscibility2011Inngår i: Journal of Materials Chemistry, ISSN 0959-9428, E-ISSN 1364-5501, Vol. 21, nr 29, s. 10676-10684Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The thermal behaviour of an organic photovoltaic (OPV) binary system comprised of a liquid-crystalline fluorene-based polymer and a fullerene derivative is investigated. We employ variable-temperature ellipsometry complemented by photo-and electroluminescence spectroscopy as well as optical microscopy and scanning force nanoscopy to explore phase transitions of blend thin films. The high glass transition temperature correlates with the good thermal stability of solar cells based on these materials. Furthermore, we observe partial miscibility of the donor and acceptor together with the tendency of excess fullerene derivative to segregate into exceedingly large domains. Thus, for charge generation less adequate bulk-heterojunction nanostructures are poised to develop if this mixture is exposed to more elevated temperatures. Gratifyingly, the solubility of the fullerene derivative in the polymer phase is found to decrease if a higher molecular-weight polymer fraction is employed, which offers routes towards improving the photovoltaic performance of non-crystalline OPV blends.

  • 177.
    Muñoz-Pineda, Eloy Guadalupe
    et al.
    Cinvestav-Unidad Queretaro, Mexico.
    Mendoza-Galván, Arturo
    Cinvestav-Queretaro, Mexico.
    Mauricio-Sánchez, Reina Araceli
    Landin, Jan
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan.
    Järrendahl, Kenneth
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan.
    Arwin, Hans
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan.
    Polarization properties and structural color of the scarab beetle Cotinis mutabilis (Mayatl)2012Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    Nature offers a plethora of possibilities for optical biomimetics. Some birds, butterflies, insects and other creatures exhibit brilliant colors as result of diverse optical phenomena produced by micro- and nanostructures at the near surface. Particularly, the shiny metallic colors reflected by the exoskeleton (the so called cuticle) of some beetles show elliptical polarization properties; most commonly of the left-handed type but also the right-handed type has been found [1]. These color and polarization properties have been related to a twisted plywood or Bouligand structure which is comprised by the clustering of chitin nanofibrils wrapped by proteins in a planar woven.

    In this work we report the polarization properties of light reflected from the scarab beetle Cotinis mutabilis (Gory and Percheron 1833) and the microstructure of its cuticle. This species is found in Mexico and the southwestern part of the United States. The specimen under study was collected at the facilities of Cinvestav in Querétaro, Mexico where it is known as mayate (Mayatl in Náuhtl, the language of Aztecs). The Mayatl presents a green mate color in its dorsal side with red-orange stripes in the elytra. On the other hand, the abdominal side shows a shiny green metallic color which is subject of the present study. The polarization properties are investigated by the complete Mueller matrix (M) measured with a dual rotating compensator ellipsometer (J. A. Woollam Co., Inc.) at angles of incidence of 20-75° and wavelength range of 250-1000 nm. In particular, the elements m41 and m14 of M show that green left-handed polarized light is reflected when the beetle is illuminated at near-normal angles of incidence with unpolarized white light. As the angle of incidence increases the maximum of light reflected is blue-shifted. The degree of polarization, ellipticity, and azimuth calculated with relationships between mj1 elements provide a full description of the polarization state of light reflected from the beetle’s cuticle for incident un-polarized light. Scanning electron microscopy images of the cuticle reveal that the epicuticle and exocuticle comprise a (hard) layer ca. 15 μm thick. Two regions can be differentiated in the exocuticle: the outer exocuticle without any clear structure and the inner exocuticle where a clear multilayer structure is observed. Beneath the inner exocuticle is the endocuticle which is comprised by unidirectional layers of microfibrils alternate with layers running at nearly right angles to each other in a pseudo-orthogonal arrangement. The cuticle also was imaged with a microscope coupled to a FTIR system allowing further identification of bands due to chitin.

  • 178.
    Muñoz-Pineda, Eloy
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan. Cinvestav-IPN, Unidad Querétaro, Libramiento Norponiente 2000, Querétaro, Mexico.
    Järrendahl, Kenneth
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan.
    Arwin, Hans
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan.
    Mendoza-Galván, Arturo
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan. Cinvestav-IPN, Unidad Querétaro, Libramiento Norponiente 2000, Querétaro, Mexico.
    Symmetries and relationships between elements of the Mueller matrix spectra of the cuticle of the beetle Cotinis mutabilis2014Inngår i: Thin Solid Films, ISSN 0040-6090, E-ISSN 1879-2731, Vol. 571, s. 660-665Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The optical properties of light reflected from the cuticle of the scarab beetle Cotinis mutabilis are studied using variable angle Mueller matrix spectroscopic ellipsometry. Reflection of left-handed polarized light is demonstrated. Large amplitude interference oscillations in the elements of the normalized Mueller matrix (M) reveal highly transparent materials comprising the beetle cuticle. Off-diagonal elements in M obey simple symmetry relationships due to the constraint in the cross-polarized reflection coefficients between p and s polarizations of chiral systems, rps = − rsp. Based on the latter constraint and further interrelationships experimentally investigated, the number of independent elements in M resulted in only six. Reciprocity is probed from measurements performed in opposite sample orientations and the effects on M due to sample rotation by 90° are discussed. The results suggest relatively large areas in the cuticle of C. mutabilis with a helicoidal structure comprised of fibrils with a well-defined orientation.

  • 179.
    Mårtensson, Niklas
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik.
    Optical Properties of Silica-Copper Oxide Thin Films Prepared by Spin Coating2011Independent thesis Basic level (degree of Bachelor), 10,5 poäng / 16 hpOppgave
    Abstract [en]

    Optical properties of copper oxide nanoparticles in a silica matrix thin film have been investigated. Films were prepared on Si substrates from a sol-gel by spin coating. Four samples with different thicknesses, from 14,5-109 nm, were fabricated. Optical properties were measured with Variable Angle Spectroscopic Ellipsometry. The aim of the project was to gain further understanding of these films that are interesting in applications for solar absorbers as solar selective coatings. Ellipsometricangles Ψ and Δ were measured in the wavelength range from 250-1700 nm. A dispersion model was developed and fitted to experimental data with acceptable results.

  • 180.
    Nilsson, Christina
    et al.
    Department of Sensor Technology, Swedish Defense Research Agency, FOI Linköping University, IFM, Tillämpad optik.
    Jänis, A.
    Department of Sensor Technology Swedish Defense Research Agency, FOI.
    Kariis, Hans
    Department of Sensor Technology Swedish Defense Research Agency, FOI.
    Arwin, Hans
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik.
    Järrendahl, Kenneth
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi.
    Combining Spectroscopic Ellipsometry and Vector Network Analysis to obtain Electromagnetic Response in a Wide Wavelength Region2007Inngår i: 4th International Conference on Spectroscopic Ellipsometry,2007, Linköping: Linköpings universitet , 2007, s. 136-Konferansepaper (Fagfellevurdert)
  • 181.
    Oates, T W H
    et al.
    Leibniz Institute Analyt Wissensch ISAS Berlin.
    Wormeester, H
    University of Twente.
    Arwin, Hans
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan.
    Characterization of plasmonic effects in thin films and metamaterials using spectroscopic ellipsometry2011Inngår i: Progress in Surface Science, ISSN 0079-6816, E-ISSN 1878-4240, Vol. 86, nr 11-12, s. 328-376Artikkel, forskningsoversikt (Fagfellevurdert)
    Abstract [en]

    In this article, spectroscopic ellipsometry studies of plasmon resonances at metal-dielectric interfaces of thin films are reviewed. We show how ellipsometry provides valuable non-invasive amplitude and phase information from which one can determine the effective dielectric functions, and how these relate to the material nanostructure and define exactly the plasmonic characteristics of the system. There are three related plasmons that are observable using spectroscopic ellipsometry; volume plasmon resonances, surface plasmon polaritons and particle plasmon resonances. We demonstrate that the established method of exploiting surface plasmon polaritons for chemical and biological sensing may be enhanced using the ellipsometric phase information and provide a comprehensive theoretical basis for the technique. We show how the particle and volume plasmon resonances in the ellipsometric spectra of nanoparticle films are directly related to size, surface coverage and constituent dielectric functions of the nanoparticles. The regularly observed splitting of the particle plasmon resonance is theoretically described using modified effective medium theories within the framework of ellipsometry. We demonstrate the wealth of information available from real-time in situ spectroscopic ellipsometry measurements of metal film deposition, including the evolution of the plasmon resonances and percolation events. Finally, we discuss how generalized and Mueller matrix ellipsometry hold great potential for characterizing plasmonic metamaterials and sub-wavelength hole arrays.

  • 182.
    Oates, Thomas W H
    et al.
    Leibniz Institute Analyt Wissensch ISAS Berlin.
    Ranjan, Mukesh
    Forschungszentrum Dresden Rossendorf eV.
    Facsko, Stefan
    Forschungszentrum Dresden Rossendorf eV.
    Arwin, Hans
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan.
    Highly anisotropic effective dielectric functions of silver nanoparticle arrays2011Inngår i: OPTICS EXPRESS, ISSN 1094-4087, Vol. 19, nr 3, s. 2014-2028Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Variable-angle and Mueller matrix spectroscopic ellipsometry are used to determine the effective dielectric tensors of random and aligned silver nanoparticles and nanorods thin films. Randomly arranged particles are uniaxially anisotropic while aligned particles are biaxially anisotropic, with the anisotropy predominantly at the plasmonic resonances. The strong resonances in nanorod arrays result in the real part of the effective in-plane permittivities being opposite in sign over a significant range in the visible, suggesting the potential to design materials that display tunable negative-refraction. A structural tilt in the particle arrays results in monoclinic dielectric properties.

  • 183.
    Olofsson, Johanna
    et al.
    Applied Materials Science, Uppsala University, Sweden.
    Grehk, Mikael
    Sandvik Materials Technology; Sandviken, Sweden.
    Berlind, Torun
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan.
    Persson, Cecilia
    Applied Materials Science, Uppsala University, Sweden.
    Jacobson, Staffan
    Applied Materials Science, Uppsala University, Sweden.
    Engqvist, Håkan
    Applied Materials Science, Uppsala University, Sweden.
    Evaluation of silicon nitride as a wear resistant and resorbable alternative for total hip joint replacement2012Inngår i: Biomatter, ISSN 2159-2527, E-ISSN 2159-2535, Vol. 2, nr 2, s. 94-102Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Many of the failures of total joint replacements are related to tribology, i.e., wear of the cup, head and liner. Accumulation of wear particles at the implants can be linked to osteolysis which leads to bone loss and in the end aseptic implant loosening. Therefore it is highly desirable to reduce the generation of wear particles from the implant surfaces.

    Silicon nitride (Si3N4) has shown to be biocompatible and have a low wear rate when sliding against itself and is therefore a good candidate as a hip joint material. Furthermore, wear particles of Si3N4 are predicted to slowly dissolve in polar liquids and they therefore have the potential to be resorbed in vivo, potentially reducing the risk for aseptic loosening.

    In this study, it was shown that α-Si3N4-powder dissolves in PBS. Adsorption of blood plasma indicated a good acceptance of Si3N4 in the body with relatively low immune response. Si3N4 sliding against Si3N4 showed low wear rates both in bovine serum and PBS compared with the other tested wear couples. Tribofilms were built up on the Si3N4 surfaces both in PBS and in bovine serum, controlling the friction and wear characteristics.

  • 184.
    Patra, Hirak Kumar
    et al.
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för cellbiologi. Linköpings universitet, Medicinska fakulteten.
    Valyukh, Sergiy
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska fakulteten.
    Wiechec, Emilia
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för neuro- och inflammationsvetenskap. Linköpings universitet, Medicinska fakulteten.
    Tiwari, Ashutosh
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biosensorer och bioelektronik. Linköpings universitet, Tekniska fakulteten.
    Turner, Anthony
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biosensorer och bioelektronik. Linköpings universitet, Tekniska fakulteten.
    Switchable label free apta-nanosensor: In situ biopsy?2016Inngår i: Biosensors 2016 – The World Congress on Biosensors, Gothenburg, Sweden, 25-27 May 2016, Elsevier, 2016Konferansepaper (Annet vitenskapelig)
  • 185.
    Persson, Nils-Krister
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska högskolan.
    Arwin, Hans
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan.
    Inganäs, Olle
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska högskolan.
    Optical optimization of polyfluorene-fullerene blend photodiodes2005Inngår i: Journal of Applied Physics, ISSN 0021-8979, E-ISSN 1089-7550, Vol. 97, nr 3, s. 034503-1-034503-8Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Blends of polyfluorene-fullerenes are promising materials for polymer-based photovoltaic devices (PPVD). Using spectroscopic ellipsometry we deduce the dielectric function for the blend of the fullerene derivative [6,6]-phenyl-C 61-butyric acid methyl ester (PCBM) and the alternating polyfluorene copolymer, poly [2,7-(9,9-dioctyl-fluorene)-alt-5,5-(4',7'-di-2-thienyl-2',1', 3'-benzothiadiazole)] DiO-PFDTBT (4:1 by weight), for the wavelength interval 250-1300 nm. n reaches above 2 and saturates to 1.9 for high wavelengths. Absorption starts at 720 nm (1.72 eV) and reaches a crest around 550 nm (2.25 eV). The spin coating introduces anisotropy in the blend, manifested in birefringence as well as in dichroism. The dielectric function for the blend versus its constituents is not additive. There are indications that the constituents lost their dielectric identity, as screening cannot explain the experimental data. Simulations of optical absorption inside a PPVD are performed for both monochromatic and polychromatic light, using an air mass 1.5 distributed solar irradiation. The model allows calculation of absorbed energies in absolute values in all layers within the device. An optimization is carried out with respect to the layer thicknesses. From a purely optical perspective there is no gain of optical absorbance in including an additional layer of acceptor. Spatially resolved energy dissipation within the device is presented for polychromatic light. Estimates for quantum efficiencies are derived. Experimental and theoretical results for reflectance are compared.

  • 186.
    Pettersson, M
    et al.
    Uppsala University, Sweden.
    Tkachenko, S
    Uppsala University, Sweden.
    Schmidt, Susann
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Berlind, Torun
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan.
    Jacobson, S
    Uppsala University, Sweden.
    Hultman, Lars
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Engqvist, H
    Uppsala University, Sweden.
    Persson, C
    Uppsala University, Sweden.
    Mechanical and tribological behavior of silicon nitride and silicon carbon nitride coatings for total joint replacements2013Inngår i: Journal of The Mechanical Behavior of Biomedical Materials, ISSN 1751-6161, E-ISSN 1878-0180, Vol. 25, s. 41-47Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Total joint replacements currently have relatively high success rates at 10–15 years; however, increasing ageing and an active population places higher demands on the longevity of the implants. A wear resistant configuration with wear particles that resorb in vivo can potentially increase the lifetime of an implant. In this study, silicon nitride (SixNy) and silicon carbon nitride (SixCyNz) coatings were produced for this purpose using reactive high power impulse magnetron sputtering (HiPIMS). The coatings are intended for hard bearing surfaces on implants. Hardness and elastic modulus of the coatings were evaluated by nanoindentation, cohesive, and adhesive properties were assessed by micro-scratching and the tribological performance was investigated in a ball-on-disc setup run in a serum solution. The majority of the SixNy coatings showed a hardness close to that of sintered silicon nitride (∼18 GPa), and an elastic modulus close to that of cobalt chromium (∼200 GPa). Furthermore, all except one of the SixNy coatings offered a wear resistance similar to that of bulk silicon nitride and significantly higher than that of cobalt chromium. In contrast, the SixCyNz coatings did not show as high level of wear resistance.

  • 187.
    Pettersson, Maria
    et al.
    Uppsala University, Sweden.
    Berlind, Torun
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan.
    Schmidt, Susann
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Jacobsson, Staffan
    Uppsala University, Sweden.
    Hultman, Lars
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Persson, Cecilia
    Uppsala University, Sweden.
    Engqvist, Håkan
    Uppsala University, Sweden.
    Structure and composition of silicon nitride and silicon carbon nitride coatings for joint replacements2013Inngår i: Surface & Coatings Technology, ISSN 0257-8972, E-ISSN 1879-3347, Vol. 235, nr 25, s. 827-834Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    SiNx and SiCxNy coatings were fabricated with high power impulse magnetron sputtering (HiPIMS). The coatings microstructure, growth pattern, surface morphology, composition, and bonding structure were investigated by AFM, SEM, GIXRD, TEM, EDS as well as XPS, and related to the deposition parameters target powers and substrate temperature. Cross-sections of SiCxNy coatings showed either dense and laminar, or columnar structures. These coatings varied in roughness (Ra between 0.2 and 3.8 nm) and contained up to 35 at.% C. All coatings were substoichiometric (with an N/Si ratio from 0.27 to 0.65) and contained incorporated particles (so called droplets). The SiNx coatings, in particular those deposited at the lower power on the silicon target, demonstrated a dense microstructure and low surface roughness (Ra between 0.2 and 0.3 nm). They were dominated by an (X-ray) amorphous structure and consisted mainly of Si–N bonds. The usefulness of these coatings is discussed for bearing surfaces for hip joint arthroplasty in order to prolong their life-time. The long-term aim is to obtain a coating that reduces wear and metal ion release, that is biocompatible, and with wear debris that can dissolve in vivo.

  • 188.
    Poksinski, Michal
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan.
    Total internal reflection ellipsometry2005Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    This thesis summarizes the work performed on the development and implementation of the optical measurement technique called total internal reflection ellipsometry (TIRE).

    The TIRE principle is based on spectroscopic ellipsometry performed under conditions of total internal reflection. This configuration is suitable for monitoring and analysis of thin semitransparent films and changes in/on these films due to exposure to various media (liquid or gas). When metal films are used this technique can be further extended with the surface plasmon resonance (SPR) effect forming a measurement method, which allows measurements with very high precision. The main advantages of TIRE are the possibility for measurements in opaque liquids and very good detection limits, both unavailable with the complementary techniques, ellipsometry and SPR, used in their conventional mode.

    The measurement principles of ellipsometry and surface plasmon resonance have been known for a long time and these techniques are currently widely used in various areas of science and technology. Furthermore, internal reflection ellipsometry has been reported several years ago and possibilities offered by this technique have been discussed by several scientists. However, so far there has been no attempt to give a more comprehensive report containing the combination of theoretical aspects, technical development and practical applications all-in-one. Therefore, the main goal of this work was to give some deeper insight into the TIRE technique by focusing on the following aspects: theoretical and mathematical tools used in TIRE and development of the measurement system with its applications. Unfolding the above - the aim of the TIRE project is to review what has been done so far in the area of TIRE and update this with the current results. Included is also developing a set of components of the TIRE measurement system, and understanding the possible technical problems which may show up, with an attempt to resolve them. Finally, the possible applications of the TIRE technique in various areas of science and technology are exemplified, with focus on the advantages over the currently used techniques.

    The TIRE technique is suitable for monitoring of adsorption/ desorption of molecules from various liquid/gas media on the surfaces of the material playing the role of the substrate, as well as for studying the material itself. Within the TIRE project three types of applications have been studied. The first was in situ studies of protein adsorption on thin metal films, with use of SPR extended TIRE. The information obtained was more precise and complete than usually obtainable from SPR and conventional ellipsometry. With appropriate technical setup there is a potential to resolve the morphology of adsorbed multi-layered protein structures with TIRE. The behaviour of proteins on metals is of great importance in many areas of bio-sciences, including medicine (e.g. implants in the human body). The other two applications studied were more technical, with possible industrial relevance: adsorption and subsequent cleaning of substances from milk (useful i.e. for pipeline monitoring in the diary industry) and studies on corrosion on thin copper layers (useful e.g. for circuit board control in the microelectronics industry).

    Delarbeid
    1. Total internal reflection ellipsometry: design of experimental setup
    Åpne denne publikasjonen i ny fane eller vindu >>Total internal reflection ellipsometry: design of experimental setup
    (engelsk)Manuskript (preprint) (Annet vitenskapelig)
    Abstract [en]

    A design of an experimental setup for total internal reflection ellipsometry is presented and possible component types are described and discussed. Advantages and drawbacks of selected designs based on selection of different components are discussed briefly and examples of applications are given.

    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-89504 (URN)
    Tilgjengelig fra: 2013-02-26 Laget: 2013-02-26 Sist oppdatert: 2013-10-14
    2. Total internal reflection ellipsometry: principles and applications
    Åpne denne publikasjonen i ny fane eller vindu >>Total internal reflection ellipsometry: principles and applications
    2004 (engelsk)Inngår i: Applied Optics, ISSN 0003-6935, E-ISSN 1539-4522, Vol. 43, nr 15, s. 3028-3036Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    A concept for a measurement technique based on ellipsometry in conditions of total internal reflection is presented. When combined with surface plasmon resonance (SPR) effects, this technique becomes powerful for monitoring and analyzing adsorption and desorption on thin semitransparent metal films as well as for analyzing the semitransparent films themselves. We call this technique total internal reflection ellipsometry (TIRE). The theory of ellipsometry under total internal reflection combined with SPR is discussed for some simple cases. For more advanced cases and to prove the concept, simulations are performed with the Fresnel formalism. The use of TIRE is exemplified by applications in protein adsorption, corrosion monitoring, and adsorption from opaque liquids on metal surfaces. Simulations and experiments show greatly enhanced thin-film sensitivity compared with ordinary ellipsometry.

    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-41347 (URN)10.1364/AO.43.003028 (DOI)55634 (Lokal ID)55634 (Arkivnummer)55634 (OAI)
    Tilgjengelig fra: 2009-10-10 Laget: 2009-10-10 Sist oppdatert: 2017-12-13
    3. Total internal reflection ellipsometry
    Åpne denne publikasjonen i ny fane eller vindu >>Total internal reflection ellipsometry
    2000 (engelsk)Inngår i: Eurosensors XIV: The 14th European Conference on Solid-State Transducers : Book of Abstracts / [ed] R. de Reus, S. Bouwstra, MIC , 2000, s. 239-242Konferansepaper, Publicerat paper (Fagfellevurdert)
    Abstract [en]

    A new measurement technique combining ellipsometry and total internal reflection is presented. This technique is called total internal reflection ellipsometry and opens new possibilities for measuring adsorption on metalsurfaces. Very promising results from protein adsorption on a gold surface are presented. Also a schematic design of the instrument used in total internal reflection ellipsometry is included. The main advantage compared to normal ellipsometry is that measurements can be done in opaque ambients because of total internal reflection.

    sted, utgiver, år, opplag, sider
    MIC, 2000
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-89506 (URN)87-899-3551-9 (ISBN)
    Konferanse
    The 14th European Conference on Solid-State Transducers, 27-30 August 2000 Copenhagen, Denmark
    Tilgjengelig fra: 2013-02-26 Laget: 2013-02-26 Sist oppdatert: 2015-03-26
    4. Protein monolayers monitored by internal reflection ellipsometry
    Åpne denne publikasjonen i ny fane eller vindu >>Protein monolayers monitored by internal reflection ellipsometry
    2004 (engelsk)Inngår i: Thin Solid Films, ISSN 0040-6090, E-ISSN 1879-2731, Vol. 455-456, s. 716-721Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    Total internal reflection ellipsometry (TIRE) in spectroscopic mode in the wavelength range 400–1200 nm is employed in situ at a solid/liquid interface for investigation of protein adsorption on thin semitransparent gold films. In this configuration, the surface plasmon resonance phenomenon gives a large enhancement of the thin film sensitivity. Adsorption of a monolayer of the protein ferritin is monitored kinetically in situ and results in a change in the ellipsometric parameter Δ of more than 90° compared to 3° in similar ellipsometric measurements on gold substrates. This large sensitivity demonstrates a potential for sensor applications. The ferritin layer optical function is modeled with a Cauchy dispersion model resulting in a layer thickness of 9.2 nm, in good agreement with the dimension of the ferritin molecules. A transition layer between the protein film and the gold layer is necessary to introduce in the model to account for interactions between the protein layer and the gold film. The large sensitivity of TIRE for thin layers opens up a pathway to analyze in detail the structure of thin protein layers provided that a further development of the experimental setup and the model for the protein layer is carried out.

    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-41359 (URN)10.1016/j.tsf.2004.01.037 (DOI)55661 (Lokal ID)55661 (Arkivnummer)55661 (OAI)
    Tilgjengelig fra: 2009-10-10 Laget: 2009-10-10 Sist oppdatert: 2017-12-13
    5. Copper corrosion monitoring with total internal reflection ellipsometry
    Åpne denne publikasjonen i ny fane eller vindu >>Copper corrosion monitoring with total internal reflection ellipsometry
    2003 (engelsk)Inngår i: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 150, nr 11, s. B536-B539Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    A technique for in situ monitoring of changes on surfaces of semitransparent thin films is presented. This technique combines ellipsometry and total internal reflection and is called total internal reflection ellipsometry. It utilizes the high surface sensitivity of ellipsometry and can be applied to detect and quantify very small changes on thin film surfaces. One example on an application is corrosion monitoring. The main advantage in comparison to ordinary ellipsometry is that measurements are done from the “back side” of the sample and thus the probe beam does not propagate through and will not be influenced by the media reacting with the surface. An overview of total internal reflection ellipsometry and results from corrosion monitoring on thin copper films are presented.

    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-46437 (URN)10.1149/1.1618224 (DOI)
    Tilgjengelig fra: 2009-10-11 Laget: 2009-10-11 Sist oppdatert: 2017-12-13
    6. In situ monitoring of metal surfaces exposed to milk using total internal reflection ellipsometry
    Åpne denne publikasjonen i ny fane eller vindu >>In situ monitoring of metal surfaces exposed to milk using total internal reflection ellipsometry
    2003 (engelsk)Inngår i: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 94, nr 3, s. 247-252Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    A technique combining ellipsometry with total internal reflection is presented. The method is called total internal reflection ellipsometry (TIRE) and is suitable for monitoring of internal surfaces which opens new possibilities for measuring adsorption on metal surfaces in opaque liquids. Results from measurements of adsorption of milk and subsequent cleaning with sodium hydroxide on metal surfaces are given. These include studies on gold, iron, and chromium surfaces. A schematic design of the instrument used in TIRE is included. The main advantages of the system are non-invasive probing, fast response, and high sensitivity. The method has potential for applications in monitoring of internal surfaces of pipelines in industrial processes.

    Emneord
    Ellipsometry, Surface cleaning, Total internal reflection
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-46471 (URN)10.1016/S0925-4005(03)00382-4 (DOI)
    Tilgjengelig fra: 2009-10-11 Laget: 2009-10-11 Sist oppdatert: 2017-12-13
    7. Total internal reflection ellipsometry: thickness sensitivity in the pm-range for protein adsorption
    Åpne denne publikasjonen i ny fane eller vindu >>Total internal reflection ellipsometry: thickness sensitivity in the pm-range for protein adsorption
    (engelsk)Manuskript (preprint) (Annet vitenskapelig)
    Abstract [en]

    Total internal reflection ellipsometry (TIRE) is used to study adsorption of human serum albumin and fibrinogen on thin gold films. TIRE shows very high sensitivity for protein mono-layers adsorbed on metal surfaces when surface plasmon resonance effects are ut ilised. The measured data, expressed in ellipsometric angles ψ and Δ are of several orders of magnitude larger in comparison to those from similar experiments performed with traditional ellipsometry. TIRE opens a new path for precise studies of organic layers adsorbed on metal surfaces, with a potential for resolving the adsorbed layer micro-structure.

    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-89558 (URN)
    Tilgjengelig fra: 2013-02-26 Laget: 2013-02-26 Sist oppdatert: 2013-10-14
  • 189.
    Poksinski, Michal
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan.
    Total internal reflection ellipsometry: principles and applications2003Licentiatavhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Spectroscopic ellipsometry has been used under conditions of total internal reflection to form a new measurement technique called Total Internal Reflection Ellipsometry. When measurement settings are appropriate for surface plasmon resonance to occur it is possible to combine the advantages of both ellipsometry and surface plasmon resonance and obtain very high sensitivity and precision. This approach forms a new ground in the sensor area. Even though the techniques like ellipsometry or surface plasmon resonance have been invented long time ago and are currently on the high level of development, and furthermore total internal reflection ellipsometry has been first reported in the middle of the 20th century, it still seems to be a terra nova among measurement techniques. In this work we make an attempt to give some more light into darkness surrounding this area.

    In this thesis the principle Internal Reflection Ellipsometry (TIRE) is presented together with its theoretical aspects and description of the measurement system. Several examples of application of TIRE are included

  • 190.
    Poksinski, Michal
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan.
    Arwin, Hans
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan.
    In situ monitoring of metal surfaces exposed to milk using total internal reflection ellipsometry2003Inngår i: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 94, nr 3, s. 247-252Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A technique combining ellipsometry with total internal reflection is presented. The method is called total internal reflection ellipsometry (TIRE) and is suitable for monitoring of internal surfaces which opens new possibilities for measuring adsorption on metal surfaces in opaque liquids. Results from measurements of adsorption of milk and subsequent cleaning with sodium hydroxide on metal surfaces are given. These include studies on gold, iron, and chromium surfaces. A schematic design of the instrument used in TIRE is included. The main advantages of the system are non-invasive probing, fast response, and high sensitivity. The method has potential for applications in monitoring of internal surfaces of pipelines in industrial processes.

  • 191.
    Poksinski, Michal
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan.
    Arwin, Hans
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan.
    Protein monolayers monitored by internal reflection ellipsometry2004Inngår i: Thin Solid Films, ISSN 0040-6090, E-ISSN 1879-2731, Vol. 455-456, s. 716-721Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Total internal reflection ellipsometry (TIRE) in spectroscopic mode in the wavelength range 400–1200 nm is employed in situ at a solid/liquid interface for investigation of protein adsorption on thin semitransparent gold films. In this configuration, the surface plasmon resonance phenomenon gives a large enhancement of the thin film sensitivity. Adsorption of a monolayer of the protein ferritin is monitored kinetically in situ and results in a change in the ellipsometric parameter Δ of more than 90° compared to 3° in similar ellipsometric measurements on gold substrates. This large sensitivity demonstrates a potential for sensor applications. The ferritin layer optical function is modeled with a Cauchy dispersion model resulting in a layer thickness of 9.2 nm, in good agreement with the dimension of the ferritin molecules. A transition layer between the protein film and the gold layer is necessary to introduce in the model to account for interactions between the protein layer and the gold film. The large sensitivity of TIRE for thin layers opens up a pathway to analyze in detail the structure of thin protein layers provided that a further development of the experimental setup and the model for the protein layer is carried out.

  • 192.
    Poksinski, Michal
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan.
    Arwin, Hans
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan.
    Total internal reflection ellipsometry: design of experimental setupManuskript (preprint) (Annet vitenskapelig)
    Abstract [en]

    A design of an experimental setup for total internal reflection ellipsometry is presented and possible component types are described and discussed. Advantages and drawbacks of selected designs based on selection of different components are discussed briefly and examples of applications are given.

  • 193.
    Poksinski, Michal
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan.
    Arwin, Hans
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan.
    Total internal reflection ellipsometry: thickness sensitivity in the pm-range for protein adsorptionManuskript (preprint) (Annet vitenskapelig)
    Abstract [en]

    Total internal reflection ellipsometry (TIRE) is used to study adsorption of human serum albumin and fibrinogen on thin gold films. TIRE shows very high sensitivity for protein mono-layers adsorbed on metal surfaces when surface plasmon resonance effects are ut ilised. The measured data, expressed in ellipsometric angles ψ and Δ are of several orders of magnitude larger in comparison to those from similar experiments performed with traditional ellipsometry. TIRE opens a new path for precise studies of organic layers adsorbed on metal surfaces, with a potential for resolving the adsorbed layer micro-structure.

  • 194.
    Poksinski, Michal
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan.
    Arwin, Hans
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan.
    Total internal reflection ellipsometry: ultrahigh sensitivity for protein adsorption on metal surfaces2007Inngår i: Optics Letters, ISSN 0146-9592, E-ISSN 1539-4794, Vol. 32, nr 10, s. 1308-1310Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Total internal reflection ellipsometry (TIRE) is used to study adsorption of human serum albumin and fibrinogen on thin gold films. TIRE shows very high sensitivity for protein monolayers adsorbed on metal surfaces when surface plasmon resonance effects are utilized. The measured data, expressed in ellipsometric angles ψ and Δ are of several orders of magnitude larger in comparison with those from similar experiments performed with traditional ellipsometry. TIRE in spectral mode opens a new path for precise studies of organic layers adsorbed on metal surfaces, with a potential for resolving the adsorbed layer microstructure.

  • 195.
    Poksinski, Michal
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan.
    Dzuho, Hasan
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan.
    Arwin, Hans
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan.
    Copper corrosion monitoring with total internal reflection ellipsometry2003Inngår i: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 150, nr 11, s. B536-B539Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A technique for in situ monitoring of changes on surfaces of semitransparent thin films is presented. This technique combines ellipsometry and total internal reflection and is called total internal reflection ellipsometry. It utilizes the high surface sensitivity of ellipsometry and can be applied to detect and quantify very small changes on thin film surfaces. One example on an application is corrosion monitoring. The main advantage in comparison to ordinary ellipsometry is that measurements are done from the “back side” of the sample and thus the probe beam does not propagate through and will not be influenced by the media reacting with the surface. An overview of total internal reflection ellipsometry and results from corrosion monitoring on thin copper films are presented.

  • 196.
    Poksinski, Michal
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan.
    Dzuho, Hasan
    Linköpings universitet, Institutionen för fysik, kemi och biologi. Linköpings universitet, Tekniska högskolan.
    Järrhed, Jan-Ove
    Linköpings universitet, Institutionen för fysik, kemi och biologi. Linköpings universitet, Tekniska högskolan.
    Arwin, Hans
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan.
    Total internal reflection ellipsometry2000Inngår i: Eurosensors XIV: The 14th European Conference on Solid-State Transducers : Book of Abstracts / [ed] R. de Reus, S. Bouwstra, MIC , 2000, s. 239-242Konferansepaper (Fagfellevurdert)
    Abstract [en]

    A new measurement technique combining ellipsometry and total internal reflection is presented. This technique is called total internal reflection ellipsometry and opens new possibilities for measuring adsorption on metalsurfaces. Very promising results from protein adsorption on a gold surface are presented. Also a schematic design of the instrument used in total internal reflection ellipsometry is included. The main advantage compared to normal ellipsometry is that measurements can be done in opaque ambients because of total internal reflection.

  • 197.
    Rehammar, R
    et al.
    Chalmers.
    Magnusson, Roger
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska fakulteten.
    Fernandez-Dominguez, A I
    University of London Imperial College of Science, Technology and Medicine.
    Arwin, Hans
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan.
    Kinaret, J M
    Chalmers.
    Maier, S A
    University of London Imperial College of Science, Technology and Medicine.
    Campbell, E E B
    University of Edinburgh.
    Optical properties of carbon nanofiber photonic crystals2010Inngår i: NANOTECHNOLOGY, ISSN 0957-4484, Vol. 21, nr 46, s. 465203-Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Carbon nanofibers (CNFs) are used as components of planar photonic crystals. Square and rectangular lattices and random patterns of vertically aligned CNFs were fabricated and their properties studied using ellipsometry. We show that detailed information such as symmetry directions and the band structure of these novel materials can be extracted from considerations of the polarization state in the specular beam. The refractive index of the individual nanofibers was found to be n(CNF) = 4.1.

  • 198.
    Rehammar, Robert
    et al.
    Department of Applied Physics, Chalmers University of Technology, Göteborg, Sweden.
    Ghavanini, Farzan Alavian
    Department of Microtechnology and Nanoscience, Chalmers University of Technology, Göteborg, Sweden.
    Magnusson, Roger
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan.
    Kinaret, Jari
    Department of Applied Physics, Chalmers University of Technology, Göteborg, Sweden.
    Enoksson, Peter
    Department of Microtechnology and Nanoscience, Chalmers University of Technology, Göteborg, Sweden.
    Arwin, Hans
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan.
    Campbell, Eleanor
    University of Edinburgh, Scotland.
    Electromechanically Tunable Carbon Nanofiber Photonic Crystal2013Inngår i: Nano letters (Print), ISSN 1530-6984, E-ISSN 1530-6992, Vol. 13, nr 2, s. 397-401Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We demonstrate an electrically tunable 2D photonic crystal array constructed from vertically alignedcarbon nanofibers. The nanofibers are actuated by applying a voltage between adjacent carbon nanofiberpairs grown directly on metal electrodes, thus dynamically changing the form factor of the photoniccrystal lattice. The change in optical properties is characterised using optical diffraction andellipsometry. The experimental results are shown to be in agreement with theoretical predictions andprovide a proof-of-principle for rapidly switchable photonic crystals operating in the visible that can befabricated using standard nanolithography techniques combined with plasma CVD growth of thenanofibers.

  • 199.
    Rehammar, Robert
    et al.
    Chalmers University of Technology, Gothenburg, Sweden.
    Magnusson, Roger
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan.
    Lassesson, Andreas
    Göteborg University, Gothenburg, Sweden.
    Arwin, Hans
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan.
    Kinaret, Jari
    Chalmers University of Technology, Gothenburg, Sweden.
    Campbell, Eleanor
    Edinburgh University, UK.
    Carbon nanofiber-based photonic crystals – fabrication, diffraction and ellipsometry investigations2011Inngår i: Carbon-Based Electronic Devices - Processing, Performance and Reliability / [ed] M. Chhowalla, R.R. Keller, M. Meyyappan, W.J. Ready, Materials Research Society, 2011, Vol. 1283, s. 28-33Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Carbon nanofibers were used as building blocks for two-dimensional photonic crystal slabs. Electron beam lithography and chemical vapor deposition were used to fabricate regular arrays and random patterns of nanofibers. The optical properties of the samples were investigated using a diffraction measurement setup, as well as reflection ellipsometry. We find that carbon nanofiber regularity has a strong effect on both diffractive and specular optical properties. This shows that ellipsometry can be a valuable tool to study properties of carbon nanofiber arrays. It also shows that carbon nanofibers provide an interesting candidate as building blocks for nanostructured optical components.

  • 200.
    Rybka, Marcin
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik.
    Optical properties of MAX-phase materials2010Independent thesis Advanced level (degree of Master (One Year)), 20 poäng / 30 hpOppgave
    Abstract [en]

     

    MAX-phase materials are a new type of material class. These materials are potentiallyt echnologically important as they show unique physical properties due to the combination of metals and ceramics. In this project, spectroscopic ellipsometry in the spectral range of 0.06 eV –6.0 eV was used to probe the linear optical response of MAX-phases in terms of the complexd dielectric function ε(ω) = ε1(ω) + iε2(ω). Measured data were fit to theoretical models using the Lorentz and generalized oscillator models. Data from seven different samples of MAX-phase materials were obtained using two ellipsometers. Each sample dielectric function was determined, including their infrared spectrum.

123456 151 - 200 of 273
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