Real-time dynamically controllable polarization holographic grating

Abstract

A novel real-time dynamic controllable polarization holographic grating (PHG) has been developed using an azobenzene liquid crystal film, achieved through a periodic recording-erasing process. During recording, two orthogonally polarized lights are utilized, while circularly polarized light (CPL) is used for erasing the grating. The effects of pump intensity and temperature on the PHG are investigated through a series of experiments and numerical simulations. Finally, a peak diffraction efficiency of 17.6% is observed at 80 °C and 30 mW/cm². The photoinduced birefringence of the PHG recorded with orthogonal circular polarizations is higher than that recorded with orthogonal linear polarizations. These findings enable customized information storage within the PHG, significantly enhancing its potential applications in optical control and storage.