Quasi-phase matched difference frequency generation in corrugation-reduced GaAs/AlGaAs periodically-inverted waveguides

Abstract

We have evaluated the conversion efficiency of difference frequency generation (DFG) around 3.4 μm in a periodically-inverted GaAs/AlGaAs waveguide whose corrugation height was reduced by using chemical mechanical polishing (CMP) process. The total propagation loss for interacting waves was decreased by suppressing the corrugations at interfaces between guiding and cladding layers. The internal conversion efficiency of DFG without Fabry-Perot enhancement was estimated to be 3.0% W-1 in a 2.1 mm long CMP waveguide. Guidelines for further increasing conversion efficiencies are also given.