Density of States and Density of the Accumulated Light Energy in Finite Cholesteric Liquid Crystal Layers with Graded Parameters

A.H. Gevorgyan, A.N. Kocharian
California State University, US

Keywords: photonics, liquid crystals, photonic density of states, eigen polarizations, photonic band gap, optical diode

Summary:

This is a multilateral investigation of optical properties of new materials in photonics consisting of a stack of right and left handed cholesteric liquid crystal (CLC) layers and stack of CLC layers and isotropic (anisotropic) media layers [1]. In particular, we focus on photonic crystals (PCs) for development of new electro-optical and photonic devices for accumulation of energy [2]. PCs exhibit photonic band gaps (PBGs) preventing light propagation in certain frequency ranges, which can be tuned by modifying internal stacked structure. The stack of CLC layers of finite thickness with spatial variation of helix pitch structures are investigated for control of energy and optical properties. The reflection, transmission and absorption (radiation) coefficients of these media are calculated, as well as the spectra of photonic density of states, non-reciprocal reflection and transmission and light accumulation. We discuss the practical application for development of various new nano elements in tunable optical devices based on liquid crystals, in particular, their application as optical diodes (locks), transistors, filters and mirrors, as well as energy accumulators and low threshold lasers. [1] A.H. Gevorgyan, A.N. Kocharian, G.A. Vardanyan, Optics Communications 259 455 2006. [2] A.H. Gevorgyan, A.N. Kocharian, Optics Communications 285 2854 2012.