FERROELECTRIC LIQUID CRYSTAL DEVICES WITH TWISTED STRUCTURE

摘要

A hybrid analog/binary electro-optic modulator using a twisted ferroelectric liquid crystal structure is provided. Ferroelectric liquid crystals with a tilt angle of between about 20~ and about 25~, preferably about 22.5~ are used. Rubbing directions for the two cell walls (relative to one another) can be varied from about 45~ to about 90~. In one embodiment, a weak buffing force is used resulting in a relatively weak anchoring energy at the surface, aligning the liquid crystal molecules without locking the molecules into the buffing directions and a high pre-tilt structure for the molecules close to the surface boundaries. In one embodiment, strong buffing is used with buffing directions offset about 45~. Use of this invention provides relatively fast response time, low required driving voltage, high contrast, and/or the ability to achieve both analog and binary operations.