Fast measurement of the phase flicker of a digitally addressable LCoS-SLM

This work studied the phase flicker of Holoeye Pluto spatial light modulator (SLM), which is a typical, pure phase and digitally addressable liquid crystal on silicon spatial light modulator (LCoS-SLM). We demonstrated a method for fast measuring the phase flicker of this kind of SLM, which uses only one photon detector to measure the intensity of the first order light diffracted by the binary grating. Our experimental results show that the higher the gray level, the more severe the phase flicker, but the average phase stability maintains about 3.1%. Our results also prove that the triangular wave model basically performs well as an approximate model of the phase flicker. Furthermore, the phase flicker waveform is mainly determined by the winner of the competition between two harmonics with frequencies of 300 Hz and 600 Hz. At the gray level of 125, the amplitude difference between the two harmonics is small, the model fails. Essentially, these results have nothing to do with the specific address voltage of the SLM, but are determined by the PWM waveform corresponding to the gray level.