Reduction of threshold voltage of polymer/cholesteric liquid crystal compositeby substitution method

Abstract

Polymer/cholesteric liquid crystal (ChLC) composites prepared by in-situ　polymerization of a ChLC and a photo-curable LC monomer enable polarization-independent phase modulation with fast response times below 1 ms. One of the problems that needs to be solved for the commercialization of these materials is the high threshold voltage; however, the improvement achieved through the optimization of the monomer concentration, the polymerization temperature and the host LC is insufficient. Here, we propose a new fabrication process in which the chiral LC in the polymer network is replaced by an achiral LC after the polymer network is formed. This new fabrication method is found to yield a lower threshold voltage and larger refractive index tuning range.