Electrically switchable, photoaddressable cholesteric liquid crystal reflectors

We report on the development of photoaddressable cholesteric liquid crystal (CLC) mixtures capable of large range color tuning as well as direct on-off electrical switching. The continuously photoaddressable CLC mixtures are based on a high HTP azo-containing chiral material mixed with an off-the-shelf nematic liquid crystal (QL9/E44). By polymer stabilizing the QL9/E44 mixture, it is demonstrated that the photoaddressable reflection of the notch can be switched on and off with an AC voltage. The novel combination of these effects has potential utility in lasing, dynamic notch filters, and spatial light modulators.