Electrically tunable total reflection of light by oblique helicoidal cholesteric

An oblique helicoidal state of a cholesteric liquid crystal (ChOH) is capable of continuous change of the pitch P in response to an applied electric field. Such a structure reflects 50 axis in the electrically tunable band determined by P/2. Here we demonstrate that at an oblique incidence of light, ChOH reflects 100 polarization. This singlet band of total reflection is associated with the full pitch P. We also describe the satellite P/2, P/3, and P/4 bands. The P/2 and P/4 bands are triplets while P/3 band is a singlet caused by multiple scatterings at P and P/2. A single ChOH cell acted upon by an electric field tunes all these bands in a very broad spectral range, from ultraviolet to infrared and beyond, thus representing a structural color device with enormous potential for optical and photonic applications.