OPTICAL-PROPERTIES OF SINGLE-LAYER NONABSORPTIVE BROAD-BAND CLC POLARIZERS

We report for the first time the results of theoretical study on the o ptical 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 configuratio n on the performance of BBCLC films and therefore provide guidance for the fabrication of high quality single layer broadband polarizers. Th e study is based on Berreman's 4x4 matrix formalism. Nonlinear pitch d istribution across the cell thickness is used in the simulation. Pitch gradient smaller than 20 nm/mu m is found necessary for high extincti on ratio for chosen material system. The extinction ratio decreases si gnificantly when the incident angle (internal angle) is greater than 2 0 degrees and an extinction revere region is found in the case of larg e angle of incidence. The theoretical results are compared with the ex perimental results of Reveo's broadband polarizers and show reasonably good agreement.