Research on pointing accuracy of liquid crystal phase array based on the variable period grating method

Liquid crystal optical phase array (LC OPA) is widely used in lidar, laser communication and laser weapons to scan and control laser beams. In order to optimize the design of LC OPA and high-precision laser beam control, we study the influence of working wavelength, number of pixels, pixel size, and effective grey levels on beam pointing accuracy. Firstly, according to the liquid crystal phase modulation principle, the effective scanning angle and diffraction efficiency of the period grating and the variable period grating methods are simulated and analyzed. Secondly, assuming the phase modulation to be equally divided by the driving voltage, the variation law of the pointing error with the working wavelength, the number of pixels, the pixel size, and the effective grey levels is simulated and analyzed. The multivariable universal formula is also derived. Thirdly, the pointing accuracy of the nonuniform phase modulation is simulated, analyzed, and com-pared with the results of the uniform phase modulation. Finally, the relationship between the effective grey levels and the pointing error is verified by experiments, and the validity of the empirical formula is preliminarily confirmed. The research results can provide a theoretical basis for the design of LC OPA.