Broadband Circular Polarizer based on Cholesteric Liquid Crystal and Cholesteric Polymer Composite Films

In this paper, a cholesteric liquid crystal (CLC) and cholesteric monomer mixture are used for broadband circular polarizer, instead of pure cholesteric polymer. In this case, the birefringence and, thus, the bandwidth of each film are both increased. More importantly, unlike the solid CLC polymeric films, diffusion process can be induced in this CLC and CLC polymer composite film so that broadband reflection is achieved as a result of pitch gradient.