Electromagnetic response of corrugated multilayer systems: mirror effect in the butterfly Dione Vanillae

CANDELA SZISCHIK; MARINA INCHAUSSANDAGUE

Congreso; Early Career Researcher Living Light 2021; 2021

Several species in nature exhibit very striking colors as a consequence of complex interactions between light and tissue?s microstructures. The butterfly Dione Vanillae is covered with bright and shiny silvery spots on its ventral wings. These spots consist of densely packed transparent scales with a bright white appearance. Using optical and electron microscopy we characterized the photonic structure of the scales. The microscopy images revealed that inside the scales there is an air-filled cavity, enclosed by an upper and a lower lamina. To investigate the optical properties of the scales, we proposed a simplified geometric model that takes into account the relevant characteristics of the structure. Then, we simulated the electromagnetic response using the Chandezon method (J. Opt. Soc. Am. 72, 839, 1982), which is especially suitable for calculating the reflectance of corrugated multilayer structures. We studied how the reflectance changes when the geometric parameters of the structure are varied. Also, the optical response for different angles of incidence was analyzed. These studies were applied to estimate the reflectance of the silvery scales and the results obtained were compared with the measured response. Finally, an analysis of the color was performed.