Flexoelectro-optic liquid crystal analog phase-only modulator with a 2π range and 1 kHz switching

We present a flexoelectro-optic liquid crystal (LC) analog phase modulator with > 2 pi phase range at a 1 kHz switching frequency. The chiral nematic LC mixture consists of the bimesogen CBC7CB with chiral dopant R5011, aligned in the uniform lying helix mode. The mixture exhibits > +/- pi/4 rotation of the optic axis for a drive voltage of +/- 21.5 V (E = +/- 4.5 V mu m(-1)). The rotation of the optic axis is converted into a phase modulation with the aid of a reflective device configuration incorporating a similar to 5 mu m LC cell, a polarizer, two quarter-wave plates, and a mirror. The residual amplitude modulation is found to be < 23%. This flexoelectro-optic phase modulator combination has the potential to enable analog spatial light modulators with very fast frame rates suitable for a range of applications.