Spiking voltages for faster switching of nematic liquid-crystal light modulators

Electrical address circuits developed for driving fast-switching ferroelectric liquid-crystal spatial light modulators (SLM) can be programmed to increase the speed of much slower responding nematic liquid-crystal SLMs. Using an addressing circuit that can switch as fast as 0.164 ms, voltages are programmed for values of phase that exceed the desired phase, and when the phase reaches the desired value, the voltage is switched to the required steady-state voltage. For a SLM that has a phase range of 3.5(pi) and that is programmed over a 2(pi) range, switching speed is reduced from 400 ms to between 71 and 77 ms. The speedup algorithm is applied to each pixel of the SLM together with a digital correction for a spatially nonuniform phase.