EFFECTS OF CHARGE SPREADING ON RESOLUTION OF OPTICALLY ADDRESSED SPATIAL LIGHT MODULATORS

A transient charge-transport model is developed to evaluate the resolution limits of optically addressed spatial light modulators. The effect of bulk charge diffusion on resolution is largely independent of the mobility in the semiconductor layer, and the resolution is limited by the lateral diffusion length of charge carriers in transit. The effects of charge drift, diffusion, and trapping at the interface between the semiconductor and the light-modulating layer depend strongly on the interface properties. The resolution ranges from 2 to 700 line pairs/mm for respective diffusion lengths of 16.1 to 0.16 μm at the interface.