Optical properties of stretched polymer dispersed liquid crystal films: Angle-dependent polarized light scattering

Abstract

A systematic experimental study of the polarization-dependent light scattering properties of uniaxially stretched polymer dispersed liquid crystal (PDLC) films with the bipolar director field structure in the micron-sized nematic droplets is presented. The space distribution of the scattered intensity as a function of the incident and scattered optical polarization, as well as the degree and azimuth of polarization of the scattered light have been measured, and the results are discussed in terms of physical parameters related to the sample structure, such as molecular alignment, droplet size, shape, orientation, etc. The main factors determining the light polarizing ability of an ordered PDLC film are discussed. On the basis of the results obtained, some potential display applications of a stretched PDLC film are proposed. In particular, the reasons are given for using such a film as a polarizing diffuser for backlit twisted nematic LCDs.