Multiguide directional coupler using switchable liquid-crystalline optical channels

摘要

A multiguide directional coupler with a gratinglike indium-tin-oxide electrode on a planar nematic liquid-crystal film is studied. The linearly polarized beam can be coupled into adjacent channels with the periodic modulation of the refractive index by applying a periodic electric field. The intensity distribution of coupling in the transverse direction varies with the distance of beam propagation. The coupling effects, which depend on the polarization of the incident beam and the temperature of the liquid crystals, are also discussed.