Wide tunable shift of the reflection band in dual frequency cholesteric liquid crystals

Opt Express. 2017 Jun 12;25(12):13314-13323. doi: 10.1364/OE.25.013314.

Abstract

Technologies featuring external control of reflected and transmitted light are lately being explored for a wide range of optical and photonic applications. Yet, the options for spectral band tuning are scarce, especially if dynamic control of either reflected or transmitted light is required. In this work we demonstrate a tunable device capable of shifting the reflected light spectrum of an impinging light using dual frequency cholesteric liquid crystals. Modulating the frequency of the applied signal, the Bragg reflection can be dynamically shifted over a wide spectral range and also switched off. This feature can be applied to color filters, augmented reality, multi-color lasers or tunable windows.