Measurement of Phase Modulation Characteristics of Liquid Crystal Spatial Light Modulator

摘要

In order to obtain the phase modulation characteristics of liquid crystal spatial light modulator (LC SLM) a polarization interference method is introduced to measure the phase shift. In this method the polarized components of the light reflected from the LC SLM will interfere with each other after crossing two polarizers. The phase shift can be determined by analyzing the interference intensity. Since the two interference components of the light travel through the same path, the measurement setup is insensitive to vibrations and air currents, and then the accuracy of the measured data can be improved. The experiment results show that the phase modulations corresponding to different pixels of the LC SLM are relatively uniform across the aperture. The phase shifts will change linearly over 0 to 2π with gray levels when the custom look-up table (LUT) is used.