Shaping and control using a 2D liquid crystal optical phased array

Liquid crystal optical phased arrays are rewritable kinoform diffractive optical elements. The control solution for such devices can be based on design optimization algorithms for diffractive optics. Diffractive optical control was demonstrated on a commercially available 2D 512 by 512 liquid crystal array. Results are discussed for fan-out gratings and 2D holograms. We show with a simple example that phase singularities naturally arise in fan-out grating phase templates, but that these singularities are not branch points and usually fall off-grid. Correction for nonideal behavior and large phase gradients ("fly-back" regions) is discussed.