Abstract

Liquid crystals have one of the largest intensity-dependent refractive indices due to both thermal effects (absorption) and molecular reorientation.¹ When coated onto a thin film waveguide, they provide a very convenient nonlinear cladding medium which has already been used to demonstrate the existence of nonlinear guided waves² and all-optical switching³ with different liquid crystal materials. In the experiment reported here we deliberately chose a liquid crystal material (K18) with a nematic-to-isotropic phase transition temperature just above room temperature and have observed bistability in guided-wave transmission.

© 1986 Optical Society of America