Phase characteristics of reflecting and transmitting type twisted nematic spatial light modulators

The phase characteristics of reflecting and transmitting type twisted nematic liquid crystal based Spatial Light Modulators (SLMs) were measured using interferometry. Device parameters like contrast, brightness, input and output polarizer angles have been optimized and SLM phase nonlinearity was reduced by higher order polynomial interpolation. Higher order aberration production ability of SLMs was tested by measuring the shift in the spots of a Shack Hartmann Sensor.