Optically controllable transflective spatial filter with high- and low-pass or notch- and band-pass functions based on a dye-doped cholesteric liquid crystal film

This study developed an optically controllable transflective spatial filter in a dye-doped cholesteric liquid crystal (DDCLC) film. The mechanism to induce the spatial filter is attributable to the photoisomerization-induced controllability of the redshift of the reflection band in the DDCLC cell. At various pumped intensities, different spatial distributions of the diffraction pattern of the object can be selected to be filtered, such that high- and low-pass or notch- and band-pass transmitted and reflected images can be simultaneously obtained, respectively.