Dual-frequency addressed infrared liquid crystal phase modulators with submillisecond response time

Dynamic response of a dual-frequency liquid crystal (DFLC) based near infrared phase modulator is investigated through numerical simulations and experiments. The relationships between the optical response times and various voltage driving conditions are studied. An optical phase retarder operating at 1.55 mu m wavelength is demonstrated by using our homemade high figure-of-merit DFLC mixture. To improve the response time, both dual-frequency addressing and high voltage overdrive methods are employed. The obtained optical rising and decay times are reduced to less than 0.5 ms for a 2 pi phase change. The optical transition curves simulated with finite element method show good agreement with our experimental results