A Novel Design to Eliminate Fringe Field Effects for Liquid Crystal on Silicon

We recently developed a new liquid crystal mode which implements finger-on-plane (FOP) type common electrodes that are fabricated in a liquid crystal on silicon (LCoS) light valve. The use of appropriate electrode geometry or shape design can help overcome the problems of crosstalk and low light efficiency prevalent in conventional LCoS. Our simulation results of FOP mode LCoS indicate that the reflectance can reach above 80% even for the worst case scenario in the frame inversion driving scheme and our device reveals low dispersion in the single cell gap configuration. We also demonstrate that our SXGA LCoS panel exhibits a crosstalk free result in the frame inversion driving scheme. The optical efficiency loss due to light diffraction from finger like electrodes is about 10%. In this study, negative and positive liquid crystals are also used in our FOP mode LCoS light valve. The experimental results reveal that the brightness and contrast ratio of the FOP mode device are better than that of the VA mode device.