Enhanced second-harmonic generation in AlGaAs/AlxOy tightly confining waveguides and resonant cavities

We demonstrate second-harmonic generation (SHG) from sub-micrometer-sized AlGaAs / AlxOy artificially birefringent waveguides. The normalized conversion efficiency is the highest ever reported. We further enhanced the SHG using a waveguide-embedded cavity formed by dichroic mirrors. Resonant enhancements as high as ~ 10x were observed. Such devices could be potentially used as highly efficient, ultracompact frequency converters in integrated photonic circuits.