Photonic crystal properties of the cuticle of Chrysina resplendens scarabs

Abstract

Extensive radiative transfer calculations to fit the more significant average spectral features displayed inmeasured reflectance spectraby cuticles ofChrysina resplendesscarabshave been carried out. A simulatedannealing approach is the starting point to optimize the values of the spatial average uric acid volume fraction,the thickness of the retarderlayerlocated between the two left-handed chiral structures in the cuticle, and theslope of the parameter describing the variation with depth of the uric acid volume fraction through the retarderlayer. Both twisted arrangements are characterized in terms of their photonic behaviors to display the variationwith depth of the photonic band gaps, effective refractive index and birefringence, wave numbers and relativedensities of states.