Abstract

The second-order nonlinear interaction between a fundamental light wave and its second harmonic results in energy transfer between the interacting waves (second harmonic generation) and modifies nonlinearly their phases (cascaded nonlinearity).¹ Whilst the energy exchange has been applied to the generation of light with new frequencies since the discovery of the effect the proposals for using the cascaded nonlinearity has gained attention just recently.² It has been shown that the second-order nonlinear phase distortions can be used for realizing control of light propagation by light, such as all-optical switching or soliton propagation.³ In today available materials the nonlinear phase shift due to cascading can be orders of magnitude larger than phase shifts produced by the third-order nonlinear refractive index. This implies that typical third-order phenomena can be implemented with Watt or even mWatt power levels in waveguide geometries on the basis of cascading.

© 1995 Optical Society of America