Inspection of complex amplitudes of spatial light modulators using moiré techniques

Abstract We propose a method to get the phase and amplitude modes of an electrically driven spatial light modulator (SLM) device using the formation of moire patterns. It is found to be a fast experimental method to visualize the complex amplitude of the SLM and it may be an excellent guide to find specific complex configurations of amplitude and phase. Experimental results and limitations of the proposal are presented using a reflective liquid crystal on silicon (LCoS SLM) modulator. With this method it has been found experimentally a phase-mostly configuration using only one polarizer, without an analyzer.