화학공학소재연구정보센터
Molecular Crystals and Liquid Crystals Science and Technology. Section A. Molecular Crystals and Liquid Crystals, Vol.301, 237-248, 1997
Optical-Properties of Single-Layer Nonabsorptive Broad-Band Clc Polarizers
We report for the first time the results of theoretical study on the optical properties of single layer non-absorptive broadband cholesteric liquid crystals (BBCLC) polarizers. The objective of this study is to understand the, effect of material parameters and sample configuration on the performance of BBCLC films and therefore provide guidance for the fabrication of high quality single layer broadband polarizers. The study is based on Berreman’s 4x4 matrix formalism. Nonlinear pitch distribution across the cell thickness is used in the simulation. Pitch gradient smaller than 20 nm/mu m is found necessary for high extinction ratio for chosen material system. The extinction ratio decreases significantly when the incident angle (internal angle) is greater than 20 degrees and an extinction revere region is found in the case of large angle of incidence. The theoretical results are compared with the experimental results of Reveo’s broadband polarizers and show reasonably good agreement.