A bioinspired broadband reflector in the VIS-NIR wavelength range

Dielectric reflectors which can be found in the shells of some gold beetles (e.g. Anopognathus parvulus and Aspidomorpha tecta) consist of a stack of alternating layers of two high- and low-refractive index materials. Inspired by these structures, here we describe irregularly staggered reflectors which can be designed to feature high reflectance in a broad wavelength band that includes entirely the visible (VIS) and partially the nearinfrared (NIR) regions ([400, 1400] nm). Given the materials and the number of layers, we use a dedicated genetic algorithm to find out the reflector configuration (i.e., the sequence of the thicknesses of the layers) maximizing the reflectance in the considered wavelength band. Some results are reported showing the characteristics of such reflectors.