Electrical Reorientation of Liquid Crystal within Silicon Macropore for Photonic Devices

摘要

We present the simulation results for the local director distribution of a nematic liquid crystal (NLC) confined inside cylindrical macropores of porous silicon (PS). The Frank free energy approach is used to describe the equilibrium configuration of the NLC in porous media. The influence of the molecular anchoring strength and of an externally applied electric field is investigated. Bruggeman approximation is used while calculating the effective refractive index of each layer in a PS multilayer structure. The reflectivity spectrum of the latter is simulated using the transfer matrix approach. Electrical tuning of a NLC-PS optical microcavity designed for resonance at lambda = 1330 nm is demonstrated. Tuning range varies from 8.5 nm up to 16 nm for weak and strong surface anchoring conditions, respectively.