Beam steering characteristics of transmission liquid crystal optical phased array(LC-OPA) were measured using ultra precision electronic autocollimator. A continuous beam steering with a constant angular resolution in the order of 20 μrad is obtained experimentally from 0° to 6° based on the method of variable period grating (VPG).Meanwhile, the angular repeatability of less than 4 μrad (RMS) has been achieved.
Liquid crystal optical phased array (LC-OPA) has been reported to be one of the promising methods to realize nonmechanical laser beam steering in free-space laser communication. The nonmechanical beam steering mechanism of LC-OPA in a free-space laser communication process is demonstrated. To analyze the steering performance of LC-OPA for a beam arriving from arbitrary directions, a theoretical model based on two-dimensional liquid crystal orient model and backward propagation method is proposed. In addition the phase characteristics are discussed both in normal and oblique incident cases, and a linear relationship between angle-of-arrival and detected incident angle is also derived. All of the theoretical results are verified by the following experiments with a good agreement.