Bistable liquid crystal in a fabry-perot etalon

摘要

An optically bistable device comprises a Fabry-Perot etalon containing intracavity liquid crystal material. Etalon mirros of deposited silver are overlaid on indium tin oxide electrodes. The electrodes provide electrical biasing means for the material, which exhibits both optical nonlinearity and electro-optic tunability of refractive index. The etalon has an interference fringe maximum at a wavelength lambda m1. the fringe is tunable to lambda m2 by applying a bias voltage across the mirrors. A light beam illuminates the etalon, the beam having a wavelength lambda s where lambda m2 is between lambda s and lambda m1. The beam intensity is sufficient to induce bistable etalon switching for a fringe at lambda m2 but not for a fringe at lambda m1. Tuning the etalon fringe electro-optically from lambda m1 to lambda m2 initiates optical bistability without the prior art requirement of either variable light intensity or an external electrical feedback loop.