Compressible photonic crystal

摘要

A compressible photonic crystal comprising a polymer with an ordered array of voids, the photonic crystal having a reflectance in a first wavelength range for light incident to its incident surface and its opposing incident surface; wherein compression against at least a portion of at least one of the surfaces shifts the reflectance to a second wavelength range in at least that portion of that surface. The crystal may be used in authentication devices of various types.