An analysis of phase modulation by liquid crystal electro-optic effects

A number of liquid crystal electro-optic effects can be used to modulate light in two dimensional arrays, such as in the twisted nematic and the ferroelectric liquid devices. For some applications of spatial light modulators (SLM), particularly those employing coherent light it is important to consider not just the intensity modulation, but also the phase modulation. Three types of liquid crystal switching are considered, starting with the well known twisted nematic device, going on to ferroelectric liquid crystals and finally considered the electroclinic effect, which although the materials are still being developed and the subject of research may offer some degree of independent phase and amplitude modulation