Integrated tunable green light source on silicon nitride.
- 2026-02-28
- Light, science & applications 15(1)
- Gang Wang
- Ozan Yakar
- Xinru Ji
- Marco Clementi
- Ji Zhou
- Christian Lafforgue
- Jiaye Wu
- Jianqi Hu
- Tobias J Kippenberg
- Camille-Sophie Brès
- PubMed: 41764200
- DOI: 10.1038/s41377-026-02222-8
Study Design
Integrated green light sources are essential for telecommunications and quantum applications, while the performance of current on-chip green light generation is still limited in power and tunability. In this work, we demonstrate green light generation in silicon nitride microresonators using photo-induced second-order nonlinearities, achieving up to 3.5 mW green power via second-harmonic generation and densely tunable over a 29 nm range. In addition, we report milliwatt-level all-optical poling (AOP) threshold, allowing for amplifier-free continuous-wave AOP. Furthermore, we demonstrate non-cascaded sum-frequency generation, leveraging the combination of AOP and simultaneous coherent frequency combs generation at 1 μm. Such comb-assisted AOP enables switching of the green light generation over an 11 nm range while maintaining the pump within a single resonance. The combination of such highly efficient photo-induced nonlinearity and multi-wavelength AOP enables the realization of low-threshold, high-power, widely-tunable on-chip green sources.