Sub-millisecond response phase modulator using a low crossover frequency dual-frequency liquid crystal

A high birefringence (n=0.292 at =633nm, 25C) and low crossover frequency (1kHz at T=25C) dual-frequency liquid crystal (DFLC) mixture was developed. The high birefringence enabled us to use a thin liquid crystal cell, which is helpful for fast response time and low operating voltage. The initially low crossover frequency allowed us to operate the DFLC device at an elevated temperature, which significantly lowers the viscosity while keeping the crossover frequency in an acceptable range (10kHz). We demonstrated a 2 phase shifter at =633nm using such a DFLC and obtained a sub-millisecond response time at T45C. This type of DFLC mixture together with elevated temperature operation opens a new way for achieving fast response time