Gallium nitride on gallium oxide substrate for integrated nonlinear optics

Gallium Nitride (GaN), being a direct bandgap semiconductor with a wide bandgap and high thermal stability, is attractive for optoelectronic and electronic applications. Furthermore, due to its high optical nonlinearity - the characteristic of all III-V semiconductors - GaN is also expected to be a suitable candidate for integrated nonlinear photonic circuits for a plethora of applications, ranging from on-chip wavelength conversion to quantum computing. In this work, the fabrication of GaN waveguides on Ga
₂
O
₃
substrate and their optical characterization to assess their feasibility for efficient four-wave mixing (FWM) is reported.