Optical Limiter Based on Phase Change Material

Thesis (Master's)--University of Washington, 2017-06Optical limiter is a potential optical device to limit input light intensity to protect optical sensitive devices. It has a large transmissivity (T) when the input intensity is low and a low transmissivity when the input intensity exceeds a certain level. Thus, there is a nonlinear transition between the high and low level of power transmittance. In this project, we proposed a design of an optical limiter by utilizing phase change material. Phase change material has a large contrast in optical properties between its amorphous and crystalline state which could be used in an optical limiter as its High-T state and Low-T state respectively. The phase changes from one state to the other state according to the input intensity within a very narrow range of the input power. Such significant change allows design of a well performing optical limiter and has promising future applications