Diffractive characteristics of the liquid crystal spatial light modulator

The liquid crystal spatial light modulator (LC SLM) is very suitablefor wavefront correction and optical testing and can produce awavefront with large phase change and high accuracy. The LC SLM iscomposed of thousands of pixels and the pixel size and shape haveeffects on the diffractive characteristics of the LC SLM. This paperinvestigates the pixel effect on the phase of the wavefront with thescalar diffractive theory. The results show that the maximum opticalpath difference modulation is 41,$mu$m to produce the paraboloidwavefront with the peak to valley accuracy better than $la$/10.Effects of the mismatch between the pixel and the period, and blackmatrix on the diffraction efficiency of the LC SLM are also analysedwith the Fresnel phase lens model. The ability of the LC SLM isdiscussed for optical testing and wavefront correction based on thecalculated results. It shows that the LC SLM can be used as awavefront corrector and a compensator.