Second-harmonic generation in stoichiometric silicon nitride glass waveguides

Integrated optical waveguides based on stoichiometric silicon nitride (SÌ3N4) grown with low pressure chemical vapor deposition (LPCVD) are of high importance for applications, e.g., in microwave photonics [1] and quantum optics [2] due to their record-low loss and broad spectral transparency range. The material's third-order nonlinearity and wide transparency have enabled efficient nonlinear conversion, specifically, supercontinuum generation with record-wide bandwidth [3, 4] and are promising for all-optical switching [5].