High-speed analog complex-amplitude liquid-crystal light modulator

A homogeneously aligned smectic A* liquid-crystal quarter-wave retarder is used to produce analog complex-amplitude modulation of light through the electroclinic effect. The device consists of a reflection-mode polarization rotative phase shifter enhanced by an asymmetric resonator. With an entrance mirror reflectivity of 70%, an analog modulation of 65% of a fringe was observed. The 10-90% response time of the liquid crystal was measured to be 25 micros at 25 degrees C.