Continuously Controllable, Wide-Angle Liquid Crystal Beam Deflector Based on the Transversal Field Effect in a Three-Electrode Cell

Abstract

A controllable, refractive, electro-optical liquid crystal (LC) beam deflector is studied both theoretically and experimentally. The principle of operation of this device is based on a beam deflection from a large gradient of refractive index, generated in an LC layer by a transversal electric field , formed between two lateral electrodes, in a simple three-electrode LC cell. A continuous, controllable deflection of a Gaussian laser beam, focused into the narrow region at the electrode gap is demonstrated. Maximum deflection angles of ~ 18 to 25 deg, depending on the LC birefringence, as well as a high deflection efficiency of up to 98% are demonstrated experimentally, backed by a theoretical analysis.