Modulator using the linear electro-optic effect of liquid crystals

摘要

This invention provides an electro-optic modulator which, in some embodiments, utilizes the linear electro-optic effect in liquid crystal materials. The liquid crystal modulator of this invention comprises a chiral smectic liquid crystal cell with electrodes to supply an electric field in a direction with a nonzero linear electro-optic coefficient, and means to suppress change in the tilt angle and azimuthal angle of the liquid crystal molecular directors. The response time of the linear electro-optic effect modulators of this invention is in the nanosecond range or faster. This modulator can be employed in Fabry-Perot or waveguide devices to provide increased modulation via multiple passes. This invention further provides for prism-coupling of light into or out of the waveguide structure whereby the modulator provides amplitude modulation, tunable filtering, or both. The prism-coupled waveguide filter is further provided for any electro-optic material, not limited to liquid crystals, and any electro-optic modulation mechanism, not limited to the linear electro-optic effect.