LiNbO3 and AlGaAs on-insulator platforms for second-harmonic generation: Comparison and perspectives

The rise of aluminum gallium arsenide on-insulator (AlGaAsOI) and lithium niobate on-insulator (LNOI) platforms presents new opportunities for advancing on-chip and ultracompact nonlinear photonic devices. In this study, we investigate theoretically and via numerical simulations second-harmonic generation (SHG) in AlGaAsOI and LNOI waveguides across a wide range of pulse widths, from the subpicosecond to the continuous- wave regime, and peak power levels spanning from milliwatts to hundreds of watts. Our research aims to identify optimal time and power regimes for achieving high SHG conversion efficiency, exploring the detrimental impact of linear and nonlinear losses as well as dispersion effects. Additionally, we assess the performance of SHG against manufacturing errors and surface roughness, comparing our findings with state-of-the-art solutions. These results offer insights into the robustness and potential applications of SHG in these advanced photonic platforms.