Nematic LC Modes and LC Phase-Gratings for Reflective Spatial Light Modulators

Single-domain nematic liquid crystal (LC) devices based on either the polarization-rotation effect or the birefringent effect or both have been investigated for reflective spatial light modulators (SLMs) which use a polarized beam splitter to separate the input light beam from its orthogonal output beam. We have evaluated each LC mode in terms of its contrast ratio, brightness, operating voltage, and its tolerance in cell-gap non-uniformity. We have studied the hybrid-aligned, the O-deg, 45-deg., and 63.6-deg.-twisted nematic LC modes which can be operated in either normally-white (NW) or normally-black (NB). We have also investigated the mixed twist nematic (MTN) and self-compensated twist nematic (SCTN) for NW and tilted homeotropic mode for NB. Two-dimensional simulations have also been carried out for both NW..