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  • 1.
    Ahuja, R.
    et al.
    Condensed Matter Theory Group, Department of Physics, Uppsala University, SE-751 21 Uppsala, Sweden.
    Arwin, Hans
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik.
    Da, Silva A.F.
    Da Silva, A.F., Instituto de Fisica, Universidade Federal da Bahia, Campus Universitario de Ondina, 40 210 340 Salvadoor, Ba, Brazil.
    Persson, C.
    Condensed Matter Theory Group, Department of Physics, Uppsala University, SE-751 21 Uppsala, Sweden.
    Osorio-Guillen, J.M.
    Osorio-Guillén, J.M., Condensed Matter Theory Group, Department of Physics, Uppsala University, SE-751 21 Uppsala, Sweden.
    Souza, De Almeida J.
    Souza De Almeida, J., Condensed Matter Theory Group, Department of Physics, Uppsala University, SE-751 21 Uppsala, Sweden.
    Araujo, C.M.
    Condensed Matter Theory Group, Department of Physics, Uppsala University, SE-751 21 Uppsala, Sweden, Instituto de Fisica, Universidade Federal da Bahia, Campus Universitario de Ondina, 40 210 340 Salvadoor, Ba, Brazil.
    Veje, E.
    Dept. of Electronic Power Eng., Technical University of Denmark, Building 325, DK-2800 Lyngby, Denmark.
    Veissid, N.
    Instituto Nac. de Pesq. Espaciais, LAS, C.P 515, 12 201 970 Sao Jose dos Campos, SP, Brazil.
    An, C.Y.
    Instituto Nac. de Pesq. Espaciais, LAS, C.P 515, 12 201 970 Sao Jose dos Campos, SP, Brazil.
    Pepe, I.
    Instituto de Fisica, Universidade Federal da Bahia, Campus Universitario de Ondina, 40 210 340 Salvadoor, Ba, Brazil, LPCC, College de France, F-75231, Paris, France.
    Johansson, B.
    Condensed Matter Theory Group, Department of Physics, Uppsala University, SE-751 21 Uppsala, Sweden.
    Electronic and optical properties of lead iodide2002Inngår i: Journal of Applied Physics, ISSN 0021-8979, E-ISSN 1089-7550, Vol. 92, nr 12, s. 7219-7224Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Electronic and optical properties of lead iodide were studied experimentally using absorption, transmission, ellipsometry, and theoretically using a full-potential linear muffin-tin-orbital method. The samples were mounted in a closed-cycle helium refrigeration system and studied at temperatures between 10 and 300 K. Band-gap energy of lead iodide was measured as a function of temperature using optical absorption. Calculations showed that there was a small anisotropy in optical properties of lead iodide, and dielectric function calculations agreed well with experiments.

  • 2.
    Akerlind, C
    et al.
    Swedish Defence Research Agency.
    Arwin, Hans
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan.
    Jakobsson, Fredrik
    Linköpings universitet, Institutionen för teknik och naturvetenskap. Linköpings universitet, Tekniska högskolan.
    Kariis, H
    Swedish Defence Research Agency.
    Järrendahl, Kenneth
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska fakulteten.
    Optical properties and switching of a Rose Bengal derivative: A spectroscopic ellipsometry study2011Inngår i: THIN SOLID FILMS, ISSN 0040-6090, Vol. 519, nr 11, s. 3582-3586Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Optical properties in terms of the complex-valued dielectric function were determined for spin-coated films of a Rose Bengal derivative using variable angle of incidence spectroscopic ellipsometry in the visible and infrared wavelength regions. In addition, the thickness and roughness of the films were determined and related to the solution concentration of Rose Bengal. Switching between two different oxidation states of the Rose Bengal derivative was investigated. The two states were chemically induced by exposure to vapors of hydrochloric acid and ammonia, respectively. A substantial and reversible change of the optical properties of the films was observed.

    Fulltekst (pdf)
    fulltext
  • 3.
    Arwin, Hans
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan.
    Adsorption of Proteins at Solid Surfaces2014Inngår i: Ellipsometry of Functional Surfaces and Films / [ed] Hinrichs, Karsten; Eichhorn Klaus-Jochen, Springer Berlin/Heidelberg, 2014, s. 29-46Kapittel i bok, del av antologi (Fagfellevurdert)
    Abstract [en]

    Ellipsometry has a very high thin film sensitivity and can resolve sub-nm changes in the thickness of a protein film on a solid substrates. Being a technique based on photons in and photons out it can also be applied at solid-liquid interfaces. Ellipsometry has therefore found many in situ applications on protein layer dynamics but studies of protein layer structure are also frequent. Numerous ex situ applications on detection and quantification of protein layers are found and several biosensing concepts have been proposed. In this chapter, the use of ellipsometry in the above mentioned areas is reviewed and experimental methodology including cell design is briefly discussed. The classical ellipsometric challenge to determine both thickness and refractive index of a thin film is addressed and an overview of strategies to determine surface mass density is given. Included is also a discussion about spectral representations of optical properties of a protein layer in terms of a model dielectric function concept and its use for analysis of protein layer structure.

  • 4.
    Arwin, Hans
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Adsorption of proteins at solid surfaces2018Inngår i: Ellipsometry of functional organic surfaces and films / [ed] Karsten Hinrichs, Klaus-Jochen Eichhorn, Cham: Springer, 2018, 2, Vol. Sidorna 31-48, s. 31-48Kapittel i bok, del av antologi (Annet vitenskapelig)
    Abstract [en]

    Ellipsometry has a very high thin film sensitivity and can resolve sub-nm changes in the thickness of protein film on solid substrates. Being a technique based on photons in and photons out it can also be applied ad solid-liquid interfaces. Ellipsometry has therefore found many in situ applications on protein layer dynamics but studies of protein layer structure are also frequent. Numerous ex situ applications on detection and quantification of protein layers are found and several biosensing concepts have been proposed. In this chapter, the use of ellipsometry in the above mentioned areas is reviewed and experimental methodology including cell design is briefly discussed. The classical ellipsometric challenge to determine both thickness and refractive index of a thin film is addressed and an overview of strategies to determine surface mass density is given. Included is also a discussion about spectral representations of optical properties of a protein layer in terms of a model dielectric function concept and its use for analysis of protein layer structure.

  • 5.
    Arwin, Hans
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan.
    Analysis of photonic structures in beetles using Mueller-matrix data2012Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    Since one hundred years it is known that some scarab beetles reflect elliptically polarized light as demonstrated by Michelson (Phil. Mag. 21(1911)544) for the beetle Chrysina resplendens. The handedness of the polarization is in a majority of cases left-handed but also right-handed polarization has been found. The polarization and color effects are generated in the outer part of the exoskeleton, the so called cuticle. Our objective is here to demonstrate that structural parameters and materials optical functions of these photonic structures can be extracted by advanced modeling of spectral multi-angle Mueller-matrix data recorded from beetle cuticles.

    A dual rotating compensator ellipsometer (RC2, J. A. Woollam Co., Inc.) is used to record normalized Mueller-matrix elements mij (i,j=1..4) in the spectral range 300 – 900 nm at angles of incidence in the range 20-75º. All measurements are performed on the scutellum (a small triangular part on the dorsal side of the beetles) with focusing optics resulting in a spot size of the order of 0.05-0.1 mm. The software CompleteEASE (J. A. Woollam Co., Inc.) is used for regression analysis. Analysis of data measured on Cetonia aurata will be presented in detail and data from other beetles in the Cetoniinae and Rutelinae subfamilies will be briefly discussed.

    A contour plot of Mueller-matrix data measured on Cetonia aurata (insert) is shown below. This beetle has a metallic shine and if illuminated with unpolarized white light it reflects left-handed polarized green light as revealed by the non-zero Mueller-matrix elements m14 and m41 in the green spectral region for angles of incidence below about 45º. This is detailed in the graph to the right which shows a spectrum for Mueller-matrix element m41at 20º as well as fitted model data. The model used for the chiral nanostructure is based on a twisted lamella structure, also called Bouligand structure. Given the complexity of the nanostructure, an excellent model fit is achieved. The obtained model parameters are the spectral variation of the refractive index of the birefringent lamellas and the pitch. Limitations and development of the model will be discussed as well as its applicability to more complex beetle cuticle structures.

    Figure. Left: Mueller-matrix data versus wavelength and angle of incidence on Cetonia aurata. Each panel shows mij, where i and j correspond to the row and column, respectively. Right: Experimental and model-generated m41at an angle of incidence of 20º.

     

    In addition, Mueller-matrix spectra are very rich in information about reflection properties and allow parameterization of polarization parameters of the reflected light, e.g. in terms of azimuth and ellipticity of the polarization ellipse and the degree of polarization (see abstract by Järrendahl).

    Fulltekst (pdf)
    fulltext
  • 6.
    Arwin, Hans
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik.
    Analysis of protein layer structure using real-time ellipsometry2007Inngår i: Deutsche Physikalische Gesellschaft DPG Srping Meeting,2007, 2007Konferansepaper (Annet vitenskapelig)
    Abstract [en]

       

  • 7.
    Arwin, Hans
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan.
    Application of ellipsometry techniques to biological materials2011Inngår i: THIN SOLID FILMS, ISSN 0040-6090, Vol. 519, nr 9, s. 2589-2592Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Ellipsometry is well-suited for bioadsorption studies and numerous reports, mainly using null ellipsometry, are found on this subject whereas investigations addressing structural properties of thin biolayers are few. Here two examples based on the use of spectroscopic ellipsometry (SE) on the latter are briefly discussed. In the first example, time evolution of thickness, spectral refractive index and surface mass density of a fibrinogen matrix forming on a silicon substrate are investigated with SE and a structural model of the protein matrix is discussed. In the second example a model dielectric function concept for protein monolayers is presented. The model allows parameterization of the optical properties which facilitates monitoring of temperature induced degradation of a protein layer. More recently, photonic structures in beetles have been studied with SE. It is shown here that full Mueller-matrix SE can resolve very complex nanostructures in scarab beetles, more specifically chiral structures causing reflected light to become circularly polarized.

  • 8.
    Arwin, Hans
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan.
    Characterization of Metamaterials with Ellipsometry2009Konferansepaper (Fagfellevurdert)
  • 9.
    Arwin, Hans
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik.
    Ellipsometry in Life Science2005Inngår i: Handbook of Ellipsometry / [ed] Harland G. Tompkins and Eugene A. Irene, Norwich, NY: William Andrew Publishing/SpringerVerlag , 2005, 1, s. 799-855Kapittel i bok, del av antologi (Annet vitenskapelig)
    Abstract [en]

      Ever progressive miniaturization of integrated circuits and breakthroughs in knowledge of biological macromolecules deriving from DNA and protein surface research are propelling ellipsometry, a measurement technique based on phase and amplitude changes in polarized light, to greater popularity in a widening array of applications. Ellipsometry, without contact and non-damaging to samples, is an ideal measurement technique to determine optical and physical properties of materials at the nano scale. With the acceleration of new instruments and applications occurring today, this book provides a much needed foundation of the science and technology of ellipsometry for scientists and engineers in industry and academia at the forefront of nanotechnology developments in instrumentation, integrated circuits, fiber optics, biotechnology, and pharmaceuticals. Divided into four sections, this comprehensive handbook covers the theory of ellipsometry, instrumentation, applications, and emerging areas.

  • 10.
    Arwin, Hans
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik.
    Ellipsometry on thin organic layers of biological interest: Characterization and applications2000Inngår i: Thin Solid Films, ISSN 0040-6090, E-ISSN 1879-2731, Vol. 377-378, s. 48-56Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The thickness resolution and in situ advantage of ellipsometry make this optical technique particularly suitable for studies of thin organic layers of biological interest. Early ellipsometric studies in this area mainly provided thickness quantification, often expressed in terms of surface mass. However, today it is possible to perform monolayer spectroscopy, e.g. of a protein layer at a solid/liquid interface, and also to resolve details in the kinetics of layer formation. Furthermore, complicated microstructures, like porous silicon layers, can be modeled and protein adsorption can be monitored in such layers providing information about pore filling and penetration depths of protein molecules of different size and type. Quantification of adsorption and microstructural parameters of thin organic layers on planar surfaces and in porous layers is of high interest, especially in areas like biomaterials and surface-based biointeraction. Furthermore, by combining ellipsometric readout and biospecificity, possibilities to develop biosensor concepts are emerging. In this report we review the use of ellipsometry in various forms for studies of organic layers with special emphasis on biologically-related issues including in situ monitoring of protein adsorption on planar surfaces and in porous layers, protein monolayer spectroscopy and ellipsometric imaging for determination of thickness distributions. Included is also a discussion about recent developments of biosensor systems and possibilities for in situ monitoring of engineering of multilayer systems based on macromolecules.

  • 11.
    Arwin, Hans
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik.
    Ellipsometry-Based Sensor Systems2006Inngår i: Encyclopedia of Sensors Vol. 3, California, USA: American Scientific Publishers , 2006, s. 329-358Kapittel i bok, del av antologi (Annet vitenskapelig)
    Abstract [en]

    Encyclopedia of Sensors is the first encyclopedia ever published in the field of sensors. The multivolume encyclopedia will provide a complete coverage of most recent advances and emerging new sensor technologies in the fields of science, engineering and medicine. Although there are many books focused on sensors however no encyclopedic reference work has been published as of today. This encyclopedia will cover all aspects of sensor science and technology dealing with all types of sensor materials, their synthesis and spectroscopic characterization, sensor designs, fabrication and manufacturing techniques, sensor probes, features, physical, chemical and biosensors, their applications in electronics, photonic and optoelectronic industries, medicine, surface sensing, food industry, environmental engineering and nanotechnology. It is written for a wide range of audience from non-scientists to active scientists and engineers, professionals and experts working in the field of sensors.

  • 12.
    Arwin, Hans
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik.
    Is ellipsometry suitable for sensor applications?2001Inngår i: Sensors and Actuators A-Physical, ISSN 0924-4247, E-ISSN 1873-3069, Vol. 92, nr 1-3, s. 43-51Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Ellipsometry is a powerful tool for optical characterization of surfaces and thin-films. Very favorable features for sensor applications are the in situ advantage, the possibility to work with non-labeled molecules and the high thickness resolution. Sub-nanometers resolution can be achieved in bioaffinity-based sensing and ppm-sensitivity in gas sensing. Ellipsometric sensor systems are based on monitoring changes in the thickness, the refractive index or the microstructure of a sensing layer. These changes are induced by the substance or process measured. A classification of sensing layers is proposed and discussed. One specific application, gas sensing based on sensor arrays, is discussed in some detail. However, the main objective is to critically discuss the possibilities for sensor applications based on ellipsometric read-out.

  • 13.
    Arwin, Hans
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan.
    Polarized reflection and nanostructure in scarab beetles studied by spectroscopic Mueller-matrix ellipsometry2012Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    Michelson showed one hundred years ago that the scarab beetle Chrysina resplendens reflects near-circular polarized light [1]. More recent Mueller-matrix methodology has been employed to detail polarization phenomena in the exoskeleton of beetles [2,3]. The polarization is in a majority of cases left-handed but also right-handed polarization has been found. In addition these beetles may exhibit beautiful structural colors. Such structures may find use in many applications and a major motivation for detailed studies of natural photonic structures is that they inspire to biomimetic applications. Here we apply spectroscopic Mueller-matrix ellipsometry on scarab beetles with objective to  model natural photonic nanostructures and to describe reflection properties in terms of polarization parameters and degree of polarization.

    The studied beetles are from the following subfamilies: Cetoniinae (Cetonia aurata and Coptomia laevis); Rutelinae (Chrysina argenteola and Chrysina resplendens); and Melolonthinae (Cyphochilus insulanus). A dual rotating compensator ellipsometer (RC2, J. A. Woollam Co., Inc.) is used to record normalized Mueller-matrix spectra in the spectral range 300 – 900 nm at angles of incidence in the range 20-70º.

    From Mueller-matrix data one can determine so called derived parameters of the reflected light including azimuth and ellipticity of its polarization ellipse and the degree of polarization. The variation of these parameters with wavelength and angle of incidence are presented for a selection of the scarab beetles above. Examples of both left-handed and right-handed polarization are shown for narrow-band and wide-band reflecting beetles and the importance of degree of polarization will be discussed.

    Structural modeling is presented on Cetonia aurata to demonstrate that structural parameters can be extracted by advanced modeling of Mueller-matrix data. Cetonia aurata has a metallic shine and if illuminated with unpolarized white light it reflects left-handed polarized green light as revealed by a non-zero Mueller-matrix elements m14 and m41 in the green spectral region. At near-normal incidence the polarization can be almost circular. A model based on a twisted lamella structure, also called Bouligand structure, is used to model this chiral nanostructure. The obtained model parameters are the spectral variation of the refractive index of the birefringent lamellas and the pitch. The model also includes a dielectric surface layer.

    Keywords: Mueller-matrix ellipsometry; scarab beetles; natural nanostructures; circular polarization

     

    References:

    1. Michelson, A. A. “On Metallic Colouring in Birds and Insects,” Phil. Mag. 21 (1911) 554-567
    2. Arwin, H., Magnusson, R., Landin, J., Järrendahl, K., “Chirality-induced polarization effects in the cuticule of scarab beetles: 100 year after Michelson”, Phil. Mag. 92 (2012) 1583-1599
    3. Hodgkinson, I., Lowrey, S., Bourke, L., Parker, A., McCall, M. W., “Mueller-matrix characterization of beetle cuticle polarized and unpolarized reflections from representative architectures”, Appl. Opt. 49 (2010) 4558-4567
  • 14.
    Arwin, Hans
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik.
    Porous Semiconductors . Science and Technology2004Inngår i: Materials of the 4th International Conference,2004, Valencia: Teobaldo Jorda y Cia , 2004, s. 138-Konferansepaper (Fagfellevurdert)
  • 15.
    Arwin, Hans
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik.
    Spectroscopic ellipsometry for characterization and monitoring of organic layers2001Inngår i: Physica status solidi. A, Applied research, ISSN 0031-8965, E-ISSN 1521-396X, Vol. 188, nr 4, s. 1331-1338Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The thickness resolution and the in situ advantage of ellipsometry make this optical technique suitable for studies of thin organic layers, especially those of biological interest. With state of the art methodology it is possible to perform monolayer spectroscopy, e.g. of a protein layer at a solid/ liquid interface and also to resolve details in the kinetics of layer formation. Furthermore, complicated microstructures, like porous silicon layers, can be characterized and protein adsorption can be monitored in porous layers providing information about pore filling and penetration depths of protein molecules of different size and type. Quantification of adsorption and determination of microstructural parameters of thin organic layers on planar surfaces and in porous layers are of large interest in areas like biomaterials, basic studies of surface-based biointeraction and for biosensor development. In this report we review the use of spectroscopic ellipsometry for studies of organic layers including protein adsorption and protein monolayer spectroscopy. Included is also a discussion about possibilities for in situ spectroscopic monitoring of engineering of multilayer systems based on macromolecules.

  • 16.
    Arwin, Hans
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan.
    Spectroscopic Ellipsometry on Protein layers: Characterization and Sensor applications2009Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Ellipsometry is very attractive for studies of biolayers including protein layers. First, its thickness resolution is well below 1 nm which is perfect for protein layers as they typically are composed of nm-sized molecules. Second, ellipsometry can be used in any transparent medium, so it can be applied to solid-liquid interfaces where many bioreactions take place. Third, molecules do not have to be labeled, as required for techniques based on fluorescence or radioactivity. One drawback is that it is not analytic if operated in the visible spectral range and in simple applications one primarily measures the optical mass on a surface. However, with high precision spectroscopic ellipsometry, structural information in protein monolayers can be obtained in some cases and chemical analysis can be performed with infrared ellipsometry.

     In this report, the use of various types of ellipsometry for studies of protein layers at air/solid and liquid /solid interfaces are reviewed. Among the methods included are spectroscopic, dynamic, internal reflection and imaging ellipsometry. Two examples of methodology for analysis are discussed in some detail. First we observe that in situ studies allow monitoring of the dynamics of protein layer growth. Modeling of layer structure by separation of refractive index and thickness from such in situ data recorded during adsorption of fibrinogen layers is presented as well as strategies for evaluation of surface mass density.

     In a second example, a model dielectric function (MDF) concept for protein layers in the UV-VIS-IR spectral range is presented. The MDF contains model parameters like resonance energies and broadenings of vibrational structures, e.g. in the amide bands. Changes in these parameters can be monitored and used to assess the conformational state in the protein layer. As an example, studies of thermally induced degradation of fibrinogen layers are presented.

     Finally potential sensor applications based on imaging and dynamic ellipsometry utilizing sub-nm thickness resolution are reviewed. The use of surface-plasmon resonance enhancement to increase resolution of internal reflection ellipsometry to pm in thickness will be discussed.

     

     

     

     

     

     

  • 17.
    Arwin, Hans
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan.
    Structural and optical properties of chiral natural photonic structures determined from spectroscopic Mueller-matrix data2012Inngår i: E-MRS 2012 Fall Meeting, 2012Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    Resume : In nature one can find advanced photonic structures which often are multifunctional. High-precision analysis of such structures is a prerequisite for a biomimetic approach to synthesize analogous structures for technical applications. Here we employ spectroscopic Mueller-matrix ellipsometry to address chiral photonic structures in scarab beetles. Such structures exhibit structural colors with metallic shine but also complex polarization properties. At the same time they are hard and lightweight components in the exoskeleton of beetles. With a dual rotating compensator ellipsometer we measure Mueller-matrix data on beetles with precision better than ±0.005 in the range 350 – 1000 nm at angles of incidence 20-75º. These Mueller matrices directly provide phenomenological descriptions of polarization properties of exoskeletons and both left-handed and right-handed near-circularly reflected light can be found. By using non-linear regression analysis with Mueller-matrix data and an appropriate structural model, one can extract structural and optical details including pitch of the helical structure, as well as thicknesses and the refractive indices of the various layers in the birefringent chitin-based materials constituting the exoskeleton. The applications of Mueller-matrix analysis will be demonstrated on a selection of photonic structures in scarab beetles including wide band non-chiral, narrow-band chiral and wide-band chiral structures.

  • 18.
    Arwin, Hans
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik.
    Summaries of contributions to the conference of the Swedish Optical Society2004Inngår i: Optik i Sverige 2004,2004, 2004, s. 41-49Konferansepaper (Fagfellevurdert)
  • 19.
    Arwin, Hans
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan.
    TIRE and SPR-enhanced SE for adsorption processes2014Inngår i: Ellipsometry of Functional Organic Surface and Films / [ed] Hinrichs, Karsten; Eichhorn, Klaus-Jochen, Springer Berlin/Heidelberg, 2014, s. 249-264Kapittel i bok, del av antologi (Fagfellevurdert)
    Abstract [en]

    Ellipsometry configurations in internal reflection mode facilitate studies of adsorption processes without the light beam passing through the medium from which adsorption occurs. Monitoring of adsorption processes on surfaces in opaque media is thus possible. If the surface in addition has a thin semitransparent metal film in which surface plasmon polaritons can be excited, one can achieve very high sensitivity to small changes in surface mass density of an adsorbed biolayer. Thickness changes as small as one pm can be resolved. In this chapter the theory for Total Internal Reflection Ellipsometry (TIRE), also called surface plasmon resonance enhanced ellipsometry, will be described and instrumentation will be briefly discussed. TIRE applied in spectroscopic as well as in angle of incidence interrogation modes will be considered. Finally applications in the areas of bioadsorption processes, biosensing, gas adsorption and biolayer imaging will be reviewed.

  • 20.
    Arwin, Hans
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    TIRE and SPR-enhanced SE for adsorption processes2018Inngår i: Ellipsometry of functional organic surfaces and films / [ed] Karsten Hinrichs, Klaus-Jochen Eichhorn, Cham: Springer, 2018, Vol. Sidorna 419-435, s. 419-435Kapittel i bok, del av antologi (Annet vitenskapelig)
    Abstract [en]

    Ellipsometry configurations in internal reflection mode facilitate studies of adsorption processes without the light beam passing through the medium from which adsorption accurs. Monitoring of adsorption processes on surfaces in opaque media is thus possible. If the surface in addition has a thin semitransparent metal film in which surface plasmon polaritons can be excited, one can achieve very high sensitivity to small changes in surface mass density of an adsorbed biolayer. Thickness changes as small as on pm can be resolved. In this chapter the theory for Total Internal Reflection Ellipsometry (TIRE), also called surface plasmon resonance enhanced ellipsometry, will be described and instrumentation will be briefly discussed. TIRE applied in spectroscopic as well as in angle of incidence interrogation modes will be considered. Finally applications in the areas of bioadsorption processes, biosensing, gas adsorption and biolayer imaging will be reviewed.

  • 21.
    Arwin, Hans
    et al.
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik.
    Askendal, Agneta
    Linköpings universitet, Institutionen för fysik, kemi och biologi.
    Berlind, Torun
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik.
    Tengvall, Pentti
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad Fysik.
    Thompson, Dan W
    Department of electrical engineering University of Nebraska.
    Tiwald, T
    Woollam, John A.
    Department of electrical engineering University of Nebraska.
    Infrared ellipsometry studies of temperature effects on multilayers of ANTI-human serum albumin and its antigen2005Inngår i: E-MRS,2005, 2005Konferansepaper (Annet vitenskapelig)
  • 22.
    Arwin, Hans
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan.
    Askendal, Agneta
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad Fysik. Linköpings universitet, Tekniska högskolan.
    Tengvall, Pentti
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad Fysik. Linköpings universitet, Tekniska högskolan.
    Thompson, Daniel W.
    University of Nebraska, Lincoln, NE, USA.
    Woollam, John A.
    J. A. Woollam Co., Inc, Lincoln, NE, USA.
    Infrared ellipsometry studies of thermal stability of protein monolayers and multilayers2008Inngår i: Physica Status Solidi. C: Current Topics in Solid State Physics, ISSN 1862-6351, Vol. 5, nr 5, s. 1438-1441Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Methodology for studies of effects of heating multilayers of human serum albumin (HSA) and anti-HSA is presented. Multilayers of anti-HSA were prepared on silicon substrates and studied with infrared spectroscopic ellipsometry equipped with a heat stage. The refractive index N = n + ik and the layer thickness are determined and the amide bands are analyzed. It is found that HSA/anti-HSA multilayers are stable for shorter times at temperatures above 100 °C, except for small thickness changes. Also pilot studies of effects of heating monolayers of proteins adsorbed on gold substrates is presented.

  • 23.
    Arwin, Hans
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan.
    Aspnes, D.E.
    North Carolina State University.
    Follow the light: Ellipsometry and polarimetry2009Inngår i: Physics Today, ISSN 0031-9228, Vol. 62, nr 5, s. 70-71Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    [No abstract available]

    Fulltekst (pdf)
    FULLTEXT01
  • 24.
    Arwin, Hans
    et al.
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik.
    Bakker, Jimmy
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik.
    Filippini, Daniel
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad Fysik.
    Lundström, Ingemar
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad Fysik.
    Computer screen photo-assisted measurement of intensity or polarization change of light upon interaction with a sample2006Patent (Annet (populærvitenskap, debatt, mm))
    Abstract [en]

    A method for measuring a property of a test sample utilizing one of the test methods ellipsometry, surface plasmon resonance and nephelometry, wherein the method includes the steps; providing a test sample being an object with which an optical interaction with light takes place, illuminating said test sample using a program controlled display as a light source, which program controlled display is composed of at least one activated pixel providing an illumination from an illuminating area of said program controlled display, arranging said program controlled display to illuminate said test sample with polarized light, detecting light emerging from said test sample utilizing a detector coupled to said program and evaluating said property from signals from said detector.

  • 25.
    Arwin, Hans
    et al.
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik.
    Bakker, Jimmy
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik.
    Lundström, Ingemar
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad Fysik.
    Filippini, Daniel
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad Fysik.
    A computer as imaging ellipsometer: biosensing at home2006Inngår i: Europtrode VIII,2006, 2006Konferansepaper (Annet vitenskapelig)
  • 26.
    Arwin, Hans
    et al.
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik.
    Baroni, M P M A
    Ventura Conceicao, M.
    Rosa, R.R.
    Persson, C.
    da Silva Jr, E.F.
    Roman, L.S.
    Nakamura, O.
    Pepe, I.
    Ferreira da Silva, A.
    Optical and morphological properties of porous diamond-like-carbon films deposited by magnetron sputtering2006Inngår i: Journal of Non-Crystalline Solids, ISSN 0022-3093, E-ISSN 1873-4812, Vol. 352, nr 32-35, s. 3734-3738Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Porous diamond-like-carbon (PDLC) thin films obtained on silicon substrate by DC low energy magnetron sputtering have been investigated by photoluminescence, transmission and reflection spectroscopy, photoacoustic and spectroscopic ellipsometry. The absorption features observed for these films show similarities with those of porous silicon (PS) as well as in the performed gradient structural pattern classification of the SFM porosity, by means of the computational GPA-flyby environment on PS and PDLC samples. The dielectric function is also calculated for the bulk diamond-like carbon using the full-potential linearized augmented plane wave method within the framework of local density approximation to density functional theory. From the measurement a low real dielectric constant of about 4.5 at 0.8 eV was found whereas the calculated e1(0) for the bulk diamond has a value of 5.5. © 2006 Elsevier B.V. All rights reserved.

  • 27.
    Arwin, Hans
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan.
    Berlind, Torun
    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.
    Fernández del Río, Lia
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan.
    Gustafson, Johan
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan.
    Landin, Jan
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biologi. Linköpings universitet, Tekniska högskolan.
    Magnusson, Roger
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan.
    Åkerlind, Christina
    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.
    Polarization effects in reflection from the cuticle of scarab beetles studied by spectroscopic Mueller-matrix ellipsometry2012Inngår i: AES 2012, Advanced Electromagnetics Symposium, 2012Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    Polarization effects in reflection from the cuticle of scarab beetles studied by spectroscopic Mueller-matrix ellipsometry

     

    H. Arwin*, T. Berlind, J. Birch, L. Fernandez Del Rio, J. Gustafson, J. Landin,

    R. Magnusson, C. Åkerlind, and K. Järrendahl

    Department of Physics, Chemistry and Biology, Linköping University, Sweden

    *corresponding author: han@ifm.liu.se

     

    Abstract- Many scarab beetles exhibit structural colors and complex polarization phenomena in reflection. These effects are characterized with spectroscopic Mueller-matrix ellipsometry in our work. The polarization ellipse of reflected light as well as the degree of polarization is presented including variations with angle of incidence and wavelength. Emphasis is on beetles showing chiral effects and structural modeling of cuticle nanostructure is discussed.

     

    Background Since one hundred years it is known that some scarab beetles reflect elliptically polarized light as demonstrated by Michelson for the beetle Chrysina resplendens [1]. The handedness of the polarization is in a majority of the cases left-handed but also right-handed polarization has been found [2,3]. The ellipticity varies with wavelength and viewing angle but can be close to +1 or -1 (right or left circular polarization, respectively) and in addition these beetles may exhibit beautiful structural colors. The polarization and color effects are generated in the outer part of the exoskeleton, the cuticle. These natural photonic structures are often multifunctional and play important roles for survival of beetles, e.g. for hiding from or scaring predators, for intraspecies communication, etc. [4]. However, such structures may find use in many commercial applications and a major motivation for detailed studies of natural photonic structures is that they inspire to biomimetic applications [5,6].

    Approach Our objective is to use spectral Mueller-matrix data on scarab beetles to parameterize reflection properties in terms of polarization parameters and degree of polarization. The studied beetles all are phytophagous and include species from the Cetoniinae subfamily (e.g. Cetonia aurata and Coptomia laevis,), the Rutelinae subfamily (e.g. Chrysina argenteola and Chrysina resplendens) and the Melolonthinae subfamily (Cyphochilus insulanus). Furthermore, structural modeling is presented on Cetonia aurata and a few more beetles to demonstrate that structural parameters can be extracted by advanced modeling of Mueller-matrix data.

    Experimental A dual rotating compensator ellipsometer (RC2, J. A. Woollam Co., Inc.) is used to record all 16 Mueller-matrix elements mij (i,j=1..4) in the spectral range 300 – 900 nm at angles of incidence in the range 20-70º. The elements are normalized to m11 and thus have values between -1 and +1. All measurements are performed on the scutellum (a small triangular part on the dorsal side of the beetles) with focusing optics resulting in a spot size of the order of 50-100 mm. The software CompleteEASE (J. A. Woollam Co., Inc.) is used for analysis.

    Results and discussion As an example, Fig. 1 shows contour plots of Mueller-matrix data measured on Cetonia aurata. This beetle has a metallic shine and if illuminated with unpolarized white light it reflects left-handed polarized green light as revealed by the non-zero Mueller-matrix elements m14 and m41 in the green spectral region for angles of incidence below about 45º. This is clearly seen in the graph to the right in Fig. 1 which shows a spectrum for Mueller-matrix element m41at 20º as well as fitted model data. A model based on a twisted lamella structure, also called Bouligand structure, is used to model the chiral nanostructure [4]. Given the complexity of the nanostructure, an excellent model fit is achieved. The obtained model parameters are the spectral variation of the refractive index of the birefringent lamellas and the pitch. The model also includes a dielectric surface layer.

     

     

     

    Fig.1. Left: Mueller-matrix data on Cetonia aurata. Each contour plot shows mij, where i and j correspond to the row and column, respectively. m11 =1 and is not shown but is replaced with a photo of the beetle. Right: Experimental and model-generated Mueller-matrix element m41at an angle of incidence of 20º.

     

    From the Mueller-matrix data one can also determine so called derived parameters including azimuth and ellipticity of the polarization ellipse and the degree of polarization. The variations of these parameters with angle of incidence are presented for a selection of scarab beetles. Examples of both left-handed and right-handed polarization effects are shown and the importance of degree of polarization will be discussed.

    Concluding remarks Mueller-matrix spectra at oblique incidence are very rich in information about reflection properties and allows parameterization of polarization parameters of the reflected light. Both left-handed and right-handed reflected light is found in scarab beetles. Mueller-matrix data can also be used for a detailed modeling of the nanostructure of the cuticle of beetles.

    AcknowledgementsFinancial support was obtained from the Knut and Alice Wallenberg foundation and the Swedish Research Council. The Museum of Natural History in Stockholm, the National Museum of Natural Science in Madrid, the Berlin Museum of Natural History and the Natural History Museum in London are acknowledged for loan of beetles.

     

    REFERENCES

    1. Michelson, A. A. “On Metallic Colouring in Birds and Insects,” Phil. Mag., 21, 554-567, 1911.
    2. Goldstein, D. H. “Polarization properties of Scarabaeidae,” Appl. Opt., 45, 7944-7950, 2006.
    3. Hodgkinson, I., Lowrey, S., Bourke, L., Parker, A. and McCall, M. W. “Mueller-matrix characterization of beetle cuticle polarized and unpolarized reflections from representative architectures,” Appl. Opt., 49, 4558-4567, 2010.
    4. Vukusic, P. and Sambles, J. R. “Photonic structures in biology,” Nature, 424, 852-855, 2003.
    5. Lenau, T. and Barfoed, M. “Colours and Metallic Sheen in Beetle Shells - A Biomimetic Search for Material Structuring Principles Causing Light Interference,” Adv. Eng. Mat., 10, 299-314. 2008.
    6. Parker, A. R. and Townley, H. E “Biomimetics of photonic nanostructures,” Nature Nanotech., 2, 347-351, 2007.
  • 28.
    Arwin, Hans
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan.
    Berlind, Torun
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan.
    Johs, Blaine
    JA Woollam Co Inc, NE USA .
    Järrendahl, Kenneth
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan.
    Cuticle structure of the scarab beetle Cetonia aurata analyzed by regression analysis of Mueller-matrix ellipsometric data2013Inngår i: Optics Express, E-ISSN 1094-4087, Vol. 21, nr 19, s. 22645-22656Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Since one hundred years it is known that some scarab beetles reflect elliptically and near-circular polarized light as demonstrated by Michelson for the beetle Chrysina resplendens. The handedness of the polarization is in a majority of cases left-handed but also right-handed polarization has been found. In addition, brilliant colors with metallic shine are observed. The polarization and color effects are generated in the beetle exoskeleton, the so-called cuticle. The objective of this work is to demonstrate that structural parameters and materials optical functions of these photonic structures can be extracted by advanced modeling of spectral multi-angle Mueller-matrix data recorded from beetle cuticles. A dual-rotating compensator ellipsometer is used to record normalized Mueller-matrix data in the spectral range 400 – 800 nm at angles of incidence in the range 25–75°. Analysis of data measured on the scarab beetle Cetonia aurata are presented in detail. The model used in the analysis mimics a chiral nanostructure and is based on a twisted layered structure. Given the complexity of the nanostructure, an excellent fit between experimental and model data is achieved. The obtained model parameters are the spectral variation of the refractive indices of the cuticle layers and structural parameters of the chiral structure.

    Fulltekst (pdf)
    fulltext
  • 29.
    Arwin, Hans
    et al.
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik.
    Boulenguez, Julie
    INSP, UMR Paris 6 and 7 University.
    Järrendahl, Kenneth
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi.
    Bertier, Serge
    INSP, UMR Paris 6 and 7 University.
    Ellipsometric study of photonic structures in wing scales of butterflies2007Inngår i: Optik i Sverige,2007, 2007Konferansepaper (Annet vitenskapelig)
    Abstract [en]

      

  • 30.
    Arwin, Hans
    et al.
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik.
    Darakchieva, Vanya
    Linköpings universitet, Institutionen för fysik, kemi och biologi.
    Paskova, Tanja
    Linköpings universitet, Institutionen för fysik, kemi och biologi.
    Paskov, Plamen
    Linköpings universitet, Institutionen för fysik, kemi och biologi.
    Monemar, Bo
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi, Materiefysik.
    Schubert, Mattias
    Department of Electrical Engineering University of Nebraska.
    Figge, S
    Hommel, D
    Haskell, B A
    Fini, P T
    Nakamura, S
    Assessment of phonon mode characteristics via infrared spectroscopic ellipsometry on a-plane GaN2005Inngår i: ICSN-6,2005, 2005Konferansepaper (Annet vitenskapelig)
  • 31.
    Arwin, Hans
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Fernandez Del Rio, Lia
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Åkerlind, Christina
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten. Swedish Def Research Agency FOI, Div Command and Control Syst, SE-58111 Linkoping, Sweden.
    Valyukh, Sergiy
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Mendoza-Galvan, A.
    CINVESTAV IPN, Mexico.
    Magnusson, Roger
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Landin, Jan
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Ekologi. Linköpings universitet, Tekniska fakulteten.
    Järrendahl, Kenneth
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    On the polarization of light reflected from beetle cuticle2017Inngår i: MATERIALS TODAY-PROCEEDINGS, ELSEVIER SCIENCE BV , 2017, Vol. 4, nr 4, s. 4933-4941Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The use of Mueller matrices for studies of polarizing properties and cuticle structure of scarab beetles are partly reviewed. Specifically we show how the polarization of the reflected light can be quantified in terms of degree of polarization and ellipticity. It is also shown that sum decomposition of Mueller matrices reveals cuticle reflection characteristics in different spectral regions, e.g. in terms of mirrors and circular polarizers. With a differential decomposition of cuticle transmission Mueller matrices, we determine the spectral variation in the fundamental optical properties circular birefringence and dichroism. (C) 2017 Elsevier Ltd. All rights reserved.

  • 32.
    Arwin, Hans
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan.
    Fernández del Río, Lia
    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.
    Comparison and analysis of Mueller-matrix spectra from exoskeletons of blue, green and red Cetonia aurata2014Inngår i: Thin Solid Films, ISSN 0040-6090, E-ISSN 1879-2731, Vol. 571, s. 739-743Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The exoskeleton, also called the cuticle, of specimens of the scarab beetle Cetonia aurata is a narrow-band reflector which exhibits metallic shine. Most specimens of C. aurata have a reflectance maximum in the green part of the spectrum but variations from blue–green to red–green are also found. A few specimens are also more distinct blue or red. Furthermore, the reflected light is highly polarized and at near-normal incidence near-circular left-handed polarization is observed. The polarization and color phenomena are caused by a nanostructure in the cuticle. This nanostructure can be modeled as a multilayered twisted biaxial layer from which reflection properties can be calculated. Specifically we calculate the cuticle Mueller matrix which then is fitted to Mueller matrices determined by dual-rotating compensator ellipsometry in the spectral range 400–800 nm at multiple angles of incidence. This non-linear regression analysis provides structural parameters like pitch of the chiral structure as well as layer refractive index data for the different layers in the cuticle. The objective here is to compare spectra measured on C. aurata with different colors and develop a generic structural model. Generally the degree of polarization is large in the spectral region corresponding to the color of the cuticle which for the blue specimen is 400–600 nm whereas for the red specimen it is 530–730 nm. In these spectral ranges, the Mueller-matrix element m41 is non-zero and negative, in particular for small angles of incidence, implicating that the reflected light becomes near-circularly polarizedwith an ellipticity angle in the range 20°–45°.

    Fulltekst (pdf)
    fulltext
  • 33.
    Arwin, Hans
    et al.
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik.
    Gavutis, M
    Linkoping Univ, Dept Phys & Measurement Technol, SE-58183 Linkoping, Sweden Vilnius State Univ, Dept Phys, Vilnius, Lithuania Univ Nebraska, Ctr Microelect & Opt Mat Res, Lincoln, NE 68588 USA Univ Nebraska, Dept Elect Engn, Lincoln, NE 68588 USA.
    Gustafsson, J
    Schultzberg, M
    Linkoping Univ, Dept Phys & Measurement Technol, SE-58183 Linkoping, Sweden Vilnius State Univ, Dept Phys, Vilnius, Lithuania Univ Nebraska, Ctr Microelect & Opt Mat Res, Lincoln, NE 68588 USA Univ Nebraska, Dept Elect Engn, Lincoln, NE 68588 USA.
    Zangooie, S
    Linkoping Univ, Dept Phys & Measurement Technol, SE-58183 Linkoping, Sweden Vilnius State Univ, Dept Phys, Vilnius, Lithuania Univ Nebraska, Ctr Microelect & Opt Mat Res, Lincoln, NE 68588 USA Univ Nebraska, Dept Elect Engn, Lincoln, NE 68588 USA.
    Tengvall, Pentti
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad Fysik.
    Protein adsorption in thin porous silicon layers2000Inngår i: Physica status solidi. A, Applied research, ISSN 0031-8965, E-ISSN 1521-396X, Vol. 182, nr 1, s. 515-520Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Porous silicon layers with thicknesses in the range 100-400 nm and average porosities in the range 38-71% were prepared by electrochemical anodization. Variable angle spectroscopic ellipsometry was used to characterize the microstructure of the layers before protein adsorption. In-situ ellipsometry was then employed tr, monitor the kinetics of fibrinogen and human serum albumin adsorption. At steady state new ellipsometric spectra were recorded to determine the total amount of adsorbed protein. Under the experimental conditions used here, the protein molecules were found to adsorb in the outermost part of the porous layer. However, human serum albumin penetrated into the porous silicon matrix at low pH and high porosity. From a methodological point of view it was found that spectroscopic ellipsometry is an appropriate tool for characterization of the microstructure of porous silicon layers and for in-situ monitoring of protein adsorption in such layers including depth profiling.

  • 34.
    Arwin, Hans
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan.
    Johs, Blaine
    J. A. Woollam Co., Inc..
    Järrendahl, Kenneth
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan.
    Analysis of Mueller-matrix data from chiral structures in exoskeletons of scarab beetles2012Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    Several species of scarab beetles exhibit extra-ordinary metallic-like structural colors. These color-generating structures also show complex polarization properties and unpolarized light can be reflected with near-circular polarization. Specimens of Cetonia aurata (Linnaeus, 1758) are here studied with a dual-rotating compensator ellipsometer using focusing probes. Mueller-matrix data are recorded with precision better than ±0.005 in the range 350 – 1000 nm for angles 20-60º. In a narrow spectral range in the green part of the spectrum, the Mueller-matrix elements m14 and m41 show large negative values and the reflected light is near-circular left-handed polarized. This effect originates from a chiral structure in the beetle exoskeleton. A twisted biaxial lamellae structure with a top dielectric layer is used in regression analysis to determine pitch of the helix and refractive indices of the chitin-based constituting materials. The applicability of this model to data from different scarab beetles is reviewed and it is found that the model show limitations for beetles with broad-band reflection, e.g. those with gold-like colors. For narrow-band optical features, the model provides an excellent fit for all 15 normalized Mueller-matrix elements over the full spectrum and angle of incidence range. Dispersion models like Cauchy, b-splines and oscillator-based models are employed for the biaxial layer and fit qualities for the tested models are compared.

  • 35.
    Arwin, Hans
    et al.
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik.
    Järrendahl, K.
    TFK .
    Ellipsometric studies of the wings of the butterfly Morpho rhetenor2006Inngår i: European Optical Society Annual Meeting,2006, 2006Konferansepaper (Annet vitenskapelig)
  • 36.
    Arwin, Hans
    et al.
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik.
    Järrendahl, Kenneth
    TFK .
    Ellipsometric studies of the wings of the butterfly Morpho rhetenor2006Inngår i: Optikdagen 2006,2006, 2006Konferansepaper (Annet vitenskapelig)
  • 37.
    Arwin, Hans
    et al.
    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.
    Landin, Jan
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Ekologi. Linköpings universitet, Tekniska högskolan.
    Boulenquez, J.
    INSP, UMR 7588, CNRS, Paris 6 and Paris 7 universities, Paris, France.
    Berthier, S.
    INSP, UMR 7588, CNRS, Paris 6 and Paris 7 universities, Paris, France.
    Ellipsometry applied to natural biophotonic structures: a review2009Konferansepaper (Fagfellevurdert)
  • 38.
    Arwin, Hans
    et al.
    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.
    Landin, Jan
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Ekologi. Linköpings universitet, Tekniska högskolan.
    Boulenquez, J.
    INSP, UMR 7588, CNRS, Paris 6 and Paris 7 universities, Paris, France.
    Berthier, S.
    INSP, UMR 7588, CNRS, Paris 6 and Paris 7 universities, Paris, France.
    Optical activity in the cuticle of the beetle Cetonia aurata studied by Mueller-matrix ellipsometry2009Konferansepaper (Fagfellevurdert)
  • 39.
    Arwin, Hans
    et al.
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik.
    Karlsson, Linda
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik.
    Kozarcanin, A.
    Thompson, D.W.
    Center for Microelectronic and Optical Materials Research and Department of Electrical Engineering University of Nebraska, USA.
    Tiwald, T.
    J.A. Woollam Co., Inc. Lincoln, USA.
    Woollam, J.A.
    Center for Microelectronic and Optical Materials Research and Department of Electrical Engineering University of Nebraska, USA.
    Carbonic anhydrase adsorption in porous silicon studied with infrared ellipsometry2005Inngår i: Physica Status Solidi (a) applications and materials science, ISSN 1862-6300, E-ISSN 1862-6319, Vol. 202, s. 1688-1692Artikkel i tidsskrift (Fagfellevurdert)
  • 40.
    Arwin, Hans
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan.
    Landin, Jan
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Ekologi. Linköpings universitet, Tekniska högskolan.
    Järrendahl, Kenneth
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan.
    Optical active cuticle structures in the beetle Cetonia aurata2008Inngår i: European Optical Society Meeting 2008, 2008, s. 67-Konferansepaper (Annet vitenskapelig)
    Abstract [en]

      

  • 41.
    Arwin, Hans
    et al.
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik.
    Landin, Jan
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi, Ekologi.
    Järrendahl, Kenneth
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi.
    Optical activity in the cuticle of the beetle Cetonia aurata2008Inngår i: Optikdagen 2008,2008, 2008Konferansepaper (Fagfellevurdert)
  • 42.
    Arwin, Hans
    et al.
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik.
    Landin, Jan
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi, Ekologi.
    Järrendahl, Kenneth
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi.
    Spectral confinement of circularly polarized reflection from the cuticle of Cetonia aurata measured by spectroscopic Mueller-matrix ellipsometry2008Inngår i: E-MRS,2008, 2008Konferansepaper (Fagfellevurdert)
  • 43.
    Arwin, Hans
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan.
    Landin, Jan
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Ekologi. Linköpings universitet, Tekniska högskolan.
    Järrendahl, Kenneth
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan.
    Boulenguez, J
    INSP .
    Berthier, S.
    INSP .
    Optical Activity in the Cuticle of the Beetle Cetonia Aurata2009Inngår i: 5th Workshop Ellipsometry, Zweibrücken, Germany, March 2-4 2009, 2009, s. 38-38Konferansepaper (Annet vitenskapelig)
  • 44.
    Arwin, Hans
    et al.
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik.
    Lundström, Ingemar
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad Fysik.
    Filippini, Daniel
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad Fysik.
    Bakker, Jimmy
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik.
    Computer screen photo-assisted ellipsometry2006Inngår i: 4th Workshop Ellipsometry,2006, 2006Konferansepaper (Annet vitenskapelig)
    Abstract [en]

      

  • 45.
    Arwin, Hans
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan.
    Magnusson, Roger
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan.
    Fernández del Río, Lia
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan.
    Landin, Jan
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Ekologi. Linköpings universitet, Tekniska högskolan.
    Mendoza-Galván, Arturo
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan. Unidad Queretaro, Queretaro, Mexico.
    Järrendahl, Kenneth
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan.
    Exploring polarization features in light reflection from beetles with structural colors2015Inngår i: Proc. SPIE  9429, Bioinspiration, Biomimetics, and Bioreplication 2015, SPIE - International Society for Optical Engineering, 2015, Vol. 9429, s. 942909-1-942909-13Konferansepaper (Fagfellevurdert)
    Abstract [en]

    A Mueller matrix of a sample can be used to determine the polarization of  reflected light  for  incident light with arbitrary polarization. The polarization can be quantified  in terms of ellipticity, polarization azimuth and degree of polarization. We apply spectroscopic Mueller-matrix ellipsometry at multiple angles of incidence  to study the cuticle of beetles and derive  polarization features for incident unpolarized light.  In particular we address chiral phenomena in scarab beetles,  the origin of their structural colors and the observed high degree of circular polarization is discussed. Results from beetles in the Scarabaeidae subfamilies Cetoniinae and Rutelinae are presented including specimens with broad-band silver- or gold-like colors with metallic shine as well as specimens with narrow-band green or red reflectors. The variation of polarization with angle of incidence and occurrence of both left-handed and right-handed polarization from a single species are presented. We also use Mueller-matrix spectra in electromagnetic modeling and show how to determine structural parameters including cuticle layer thicknesses and optical properties. Interference oscillations in the observed spectra are due to allowed optical modes and we show how to develop a structural model of a cuticle based on this effect. Sum decomposition of  Mueller matrices measured on a depolarizing cuticle of a beetle is briefly discussed.

    Fulltekst (pdf)
    fulltext
  • 46.
    Arwin, Hans
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan.
    Magnusson, Roger
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan.
    Fernández del Río, Lia
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan.
    Åkerlind, Christina
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan. Swedish Defence Research Agency, Linköping, Sweden.
    Muñoz-Pineda, Eloy
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan. Cinvestav-IPN, Unidad Querétaro, Libramiento Norponiente 2000, 76230 Querétaro, Mexico.
    Landin, Jan
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biologi. 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, 76230 Querétaro, Mexico.
    Järrendahl, Kenneth
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan.
    Exploring optics of beetle cuticles with Mueller-matrix ellipsometry2014Inngår i: Materials Today, ISSN 1369-7021, E-ISSN 1873-4103, Vol. 1S, s. 155-160Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Spectroscopic Mueller-matrix ellipsometry at variable angles of incidence is applied to beetle cuticles using a small (50 -100 μm) spot size. It is demonstrated how ellipticity and degree of polarization of the reflected light can be derived from a Mueller matrix providing a detailed insight into reflection properties. Results from Cetonia aurata, Chrysina argenteola and Cotinis mutabilis are presented. The use of Mueller matrices in regression analysis to extract structural and optical parameters of cuticles is briefly described and applied to cuticle data from Cetonia aurata whereby the pitch of the twisted layered structure in the cuticle is determined as well as the refractive indices of the epicuticle and the exocuticle.

  • 47.
    Arwin, Hans
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska fakulteten.
    Magnusson, Roger
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska fakulteten.
    Garcia-Caurel, Enric
    CNRS 91128 Palaiseau, France.
    de Martino, Antonello
    CNRS 91128 Palaiseau, FranceCNRS 91128 Palaiseau, France.
    Järrendahl, Kenneth
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska fakulteten.
    Ossikovski, Razvigor
    CNRS 91128 Palaiseau, France.
    Sum decomposition of Mueller matrices from beetle cuticles2015Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    Spectral Mueller matrices are very rich in information about physical properties of a sample. We have recently shown that polarizing properties like ellipticity and degree of polarization can be extracted from a Mueller matrix measured on a beetle cuticle (exoskeleton). Mueller matrices can also be used in regression analysis to model nanostructures in cuticles. Here we present the use of sum decomposition of Mueller matrices from these depolarizing biological reflectors to explore the fundamental character of these reflectors. The objective is to decompose a Mueller matrix into well- defined ideal non-depolarizing matrices corresponding to mirrors, circular polarizers, halfwave retarders etc.Generally it is possible to decompose a measured depolarizing Mueller matrix M into four (or fewer) non-depolarizing matrices according to M=λ1M1+λ2M2+λ3M3+λ4M4, where λ1, λ2, λ3 and λ4 are eigenvalues of the covariance matrix of M. Two strategies for decomposition will be discussed. A Cloude decomposition will provide the eigenvalues and also the Mi’s although the latter will contain severe noise in some spectral regions. However, a major advantage with the Cloude decomposition is that the number of nonzero eigenvalues is directly obtained, i.e. the number of contributing Mi matrices. In an alternative decomposition, the Mi’s are assumed and the eigenvalues are found by regression analysis based on M. In the case with two non-zero eigenvalues we define a model Mueller matrix MD=αRM1+βRM2 with αR+βR=1. With αR as adjustable parameter, the Frobenius norm ||M-MD|| is minimized for each wavelength in the spectral range of M. For more complex structures, the regression can be extended by adding more matrices up to a total of four. Advantages with a regression approach are its simplicity and stability compared to a Cloude decomposition.Mueller-matrix spectra of beetle cuticles are recorded with a dual rotating compensator ellipsometer in the spectral range 400 – 900 nm at angles of incidence in the range 20 - 75°. The application of decomposition on biological reflectors is demonstrated on M measured on the beetle Cetonia aurata, which represents a narrow-band chiral Bragg reflector with two non-zero eigenvalues. A decomposition in an ideal mirror and a circular polarizer is feasible. In another example, the broad-band and gold-colored beetle Chrysina argenteola, we show that more than two eigenvalues can be nonzero, especially at oblique incidence, and additional matrices are involved.

    Fulltekst (pdf)
    fulltext
  • 48.
    Arwin, Hans
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan.
    Magnusson, Roger
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska fakulteten.
    Garcia-Caurel, Enric
    Laboratoire des Physique des Interfaces et Couches Minces, Ecole Polytechnique, CNRS, France.
    Fallet, C.
    Bioaxial SAS, 40 rue de Paradis, France.
    Järrendahl, Kenneth
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan.
    Foldyna, M.
    Laboratoire des Physique des Interfaces et Couches Minces, Ecole Polytechnique, CNRS, France.
    De Martino, A.
    Laboratoire des Physique des Interfaces et Couches Minces, Ecole Polytechnique, CNRS, France.
    Ossikovski, R.
    Laboratoire des Physique des Interfaces et Couches Minces, Ecole Polytechnique, CNRS, France.
    Sum decomposition of Mueller-matrix images and spectra of beetle cuticles2015Inngår i: Optics Express, E-ISSN 1094-4087, Vol. 23, nr 3, s. 1951-1966Artikkel i tidsskrift (Fagfellevurdert)
    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.

    Fulltekst (pdf)
    fulltext
  • 49.
    Arwin, Hans
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Magnusson, Roger
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Järrendahl, Kenneth
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Schoeche, Stefan
    JA Woollam Co Inc, NE 68508 USA.
    Effective structural chirality of beetle cuticle determined from transmission Mueller matrices using the Tellegen constitutive relations2020Inngår i: Journal of Vacuum Science and Technology B: Nanotechnology and Microelectronics, ISSN 2166-2746, E-ISSN 2166-2754, Vol. 38, nr 1, artikkel-id 014004Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Several beetle species in the Scarabaeoidea superfamily reflect left-handed polarized light due to a circular Bragg structure in their cuticle. The right-handed polarized light is transmitted. The objective here is to evaluate cuticle chiral properties in an effective medium approach using transmission Mueller matrices assuming the cuticle to be a bianisotropic continuum. Both differential decomposition and nonlinear regression were used in the spectral range of 500-1690nm. The former method provides the sample cumulated birefringence and dichroic optical properties and is model-free but requires a homogeneous sample. The materials chirality is deduced from the circular birefringence and circular dichroic spectra obtained. The regression method requires dispersion models for the optical functions but can also be used in more complex structures including multilayered and graded media. It delivers the material properties in terms of model functions of materials permittivity and chirality. The two methods show excellent agreement for the complex-valued chirality spectrum of the cuticle.

    Fulltekst (pdf)
    fulltext
  • 50.
    Arwin, Hans
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan.
    Magnusson, Roger
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan.
    Landin, Jan
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Ekologi. Linköpings universitet, Tekniska högskolan.
    Järrendahl, Kenneth
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad optik. Linköpings universitet, Tekniska högskolan.
    Chirality-induced polarization effects in the cuticle of scarab beetles: 100 years after Michelson2012Inngår i: Philosophical Magazine, ISSN 1478-6435, E-ISSN 1478-6443, Vol. 92, nr 12, s. 1583-1599Artikkel i tidsskrift (Fagfellevurdert)
    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.

    Fulltekst (pdf)
    fulltext
12345 1 - 50 of 242
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