All-optical switching in a high-Q Fabry-Perot cavity filled with a quadratic material

A theoretical analysis of the nonlinear quadratic interaction between two m onochromatic plane waves at frequencies omega and 2 omega in a Fabry-Perot cavity shows that all-optical control of reflectivity and transmissivity of the fundamental beam is possible under suitable conditions. We report all- optical switching of the fundamental beam for cavity lengths that vary from a few micrometers to a few millimeters. Specifically, we show that 100% al l-optical switching can occur for a 6-mu m cavity when the nonlinear coeffi cient is not greater than 20 pm/V and the input intensity does not exceed 1 0 GW/cm(2). Our analytical results are obtained without use of the slowly v arying envelope approximation and without resort to the undepleted-pump app roximation. (C) 2000 Optical Society of America [S0740-3224(00)00607-X].