In this report the possibility to explore the polarization properties of the wing scales of Morpho butterflies using spectroscopic ellipsometry is presented. Measurements were performed on the dorsal sides of three species of the Morpho family, rhetenor, menelaus and sulkowskyi, to compare the polarization properties of nanostructures in the wings. In these species colouration changes under polarized light were observed and all the wing scales are flat. Their photonic structures have the same general shape; they dier, mainly in terms of size and number of layers. The instrument used is a double rotating compensator ellip- someter working in the spectral range 245 nm-1700 nm. This type of instrument can measure the Mueller matrix of a sample. The Morpho rhetenor geometrical structure is known from scanning electron micrographs. Based on this structure, a Bruggeman eective