Mid-Infrared Frequency Generation via Intermodal Difference Frequency Generation in AlGaAs-On-Insulator Waveguides

We investigate theoretically mid-infrared (MIR) generation via difference frequency in multimode AlGaAs-on insulator (AlGaAs-OI) waveguides. The large refractive index between the AlGaAs core and silica cladding shrinks modes size down to sub- ?m 2 scale, and, together with strong second-order nonlinear polarization, empowers effects. As a result, efficient MIR is obtained few-cm long waveguides transverse section, where higher order are exploited achieve phase-matching condition. These observations suggest that AlGaAs-OI could represent novel promising platform for on-chip, compact sources.