Electronic compensation for nonideal spatial light modulator characteristics

Abstract

Compensation for spatial light modulator device imperfections can be achieved using digital electronics. Optical computing applications, requiring accurate phase or amplitude modulation, can then make use of low-cost, enhanced devices. Using electronic compensation, corrections can be made for a nonsquare aspect ratio in the aperture window and a nonlinear phase response{\textemdash}which may also be nonuniform over the aperture. The corrections for these imperfections are implemented using low-cost field programmable gate arrays. This technology enables real-time compensation and is easily adapted to suit a wide range of display devices. The performance enhancement is demonstrated using a popular Seiko-Epson liquid crystal television display operating as a phase modulating spatial light modulator. These developments greatly extend the utility of readily available, inexpensive, spatial light modulators.