Nonlinear directional coupler with an asymmetrical nematic liquid crystal film

The analysis of a nonlinear directional coupler consisted of two planar waveguides separated by an asymmetrical nematic liquid crystal film is presented. The nonolinear effect is caused by an optically induced reorientational effect occurring in a hybrid aligned nematic geometry. The asymmetrical configuration cuases the nonreciprocity in switching characteristics of the directional coupler.