Color-selecting reflectors inspired from biological periodic multilayer structures

Abstract

We propose a semi-infinite 1-D photonic crystal approach for designing artificial reflectors which aim to reproduce color changes with the angle of incidence found in biological periodic multilayer templates. We show that both the dominant reflected wavelength and the photonic bandgap can be predicted and that these predictions agree with exact calculations of reflectance spectra for a finite multilayer structure. In order to help the designer, the concept of spectral richness of angle-tuned color-selecting reflectors is introduced and color changes with angle are displayed in a chromaticity diagram. The usefulness of the photonic crystal approach is demonstrated by modelling a biological template (found in the cuticle of Chrysochora vittata beetle) and by designing a bio-inspired artificial reflector which reproduces the visual aspect of the template. The bioinspired novel aspect of the design relies on the strong unbalance between the thicknesses of the two layers forming the unit cell.

Polarized iridescence of the multilayered elytra of the Japanese jewel beetle,Chrysochroa fulgidissima

“…Similar layered structures have been demonstrated to exist in other Buprestidae, e.g. the jewel beetles Chrysochroa vittata [6,7], Chrysochroa fulgidissima [8,9] and Chrysochroa raja [10].…”

“…Previous optical studies of the iridescence of jewel beetles have attempted to establish a quantitative description of measured reflectance spectra using multilayer modelling [8,10] and furthermore have shown that the beetles' photonic structures can inspire biomimetic applications [6]. Here, we extend the previous work by presenting a comprehensive set of reflectance spectra, measured as a function of angle and polarization.…”

Spectral and spatial properties of polarized light reflections from the arms of squid (Loligo pealeii) and cuttlefish (Sepia officinalisL.)

“…Theory predicts that varying the angle of incidence of light falling on a multilayer reflector should result in a gradual shift of the dominant reflected wavelengths (Huxley, 1968;Land, 1972;Deparis et al, 2006). It has been shown in several squid species that, at least for the mantle area, altering the illumination angle does shift the reflectance and polarization spectra in a predictable way (Mäthger and Denton, 2001;.…”

Discovery of ordered and quasi-ordered photonic crystal structures in the scales of the beetle Eupholus magnificus

“…For instance, butterflies, beetles, birds and even aquatic systems utilize the optical properties of one, two, and three-dimensional photonic crystals to enhance and control display or crypsis [12][13][14]. One-dimensional systems include the multilayer structure of many species of beetle [8,15,16], butterflies [17] and fish [18]. Two-dimensional structures include the two-dimensional hexagonal structure found in the polychaete worm [19].…”