Thermo-optically tuned parametric wavelength conversion in integrated Bragg gratings

Abstract

We demonstrate thermo-optic tuning of parametric wavelength conversion in integrated Bragg gratings- an approach that enables dynamic control of nonlinear optical processes on-chip. Bragg gratings offer enhanced phase matching through sharp dispersion near the photonic stopband, enabling significantly improved four-wave mixing efficiency compared to uniform photonic waveguides. Leveraging this grating-induced dispersion, we achieve continuous-wave four-wave mixing with a 20 dB enhancement in on/off conversion efficiency relative to a reference waveguide of the same length. Crucially, we show that thermal tuning from 25 °C to 75 °C yields up to a 5 dB modulation in conversion efficiency and induces a 5 nm spectral shift in the stopband-representing a level of control not attainable in conventional waveguides. Experimental results show good agreement with theoretical predictions. These results establish integrated Bragg gratings as a powerful and reconfigurable platform for actively tunable nonlinear photonic devices.