Abstract

Recently, the use of a cascaded second order nonlinearity has been proposed for all-optical switching [1]. Standard coupled-wave theory of second-harmonic generation (SHG) shows that the pump wave undergoes a nonlinear phase shift when the SHG process is phase- mismatched. This has led to the proposal of a number of novel switching devices, including a push-pull Mach-Zehnder switch [2], Looking at the origins of linear and nonlinear polarization, a common feature, if the refractive index is to change, is that a frequency component in the driving fields should appear in the resulting nonlinear polarization.

© 1993 Optical Society of America