Guided wave spatial transients under a limited grating coupler in a silicon-on-sapphire waveguide
Abstract
The limited size of a grating coupler on a waveguide is responsible for the nonuniform guided wave intensity. Spatial transients have been recorded and a characteristic length of the order of 30 μm has been determined by fitting a simple model to the experimental results. This value is consistent with spatial transient measurements performed under nonlinear operation conditions which reveal a 100 μm long dead zone in which switching contrast is very low.