All-optical switching by use of cascading of phase-matched sum-frequency generation and difference-frequency generation processes

Abstract

We have investigated proposed all-optical switching by use of cascading of phase-matched sum-frequency-generation (SFG) and difference-frequency-generation (DFG) processes. The switching operation is accomplished by both a π phase change and an amplitude change of the signal field in SFG–DFG processes. We theoretically confirmed that the proposed switch requires the least operation power of any switch that uses cascading SFG–DFG processes. The switching characteristics have been numerically clarified, and the experimental full-switching characteristics when a bulk-type periodically poled LiNbO3 is used correspond to the numerical analysis. An ultrafast all-optical switch with low switching power and small size can be expected from use of waveguide-type devices.