General algorithm to optimize the diffraction efficiency of a phase-type spatial light modulator.

We present a general approach for optimizing the diffraction efficiency of a phase-type spatial light modulator (SLM). While the SLM displays a one-dimensional phase grating, the phase shift of one pixel in the grating is varied and the first-order diffraction efficiency is measured. This is repeated pixel-by-pixel to find the optimum phase encoding for the device that maximizes the diffraction efficiency. This method compensates for nonlinearity of the modulator phase response and is especially useful for optimizing modulators with less than 2π phase shift.