Design of nonlinear GaAs/AlGaAs second harmonic converters

In this work we present the design of a three-dimensional wavelength converter consisting of GaAs/AlGaAs nonlinear ridge waveguide with a quasi-phase-matched grating. A fundamental mode at λFU=1.55μm, and a copropagating second harmonic mode at λSH=0.775μm are considered. The second harmonic generation process in the χ(2) nonlinear waveguides is analysed by analytical and numerical approaches. The numerical approach is performed by the Hertzian potential formulation typically used for the modelling of χ(2) nonlinear processes. A good agreement between analytical and numerical results is observed.