Tunable band structures in uniaxial multilayer stacks

Abstract

We demonstrate highly tunable one-dimensional photonic band structures under normal incidence. The system consists of a multilayer film that alternates two anisotropic layers. The band-structure characteristics of this multilayer stack, such as location and width of stop bands, can be tailored by altering the relative orientation of the optical axes of the adjacent layers. This structure can be realized by employing liquid crystals and transparent electrodes. In some cases, we observe the ability of this structure to distinguish between different linear polarizations. We propose a depolarizing and filtering device based on this multilayer medium.