English

Self-cooling, blue-detuned dissipative Kerr microresonator soliton comb

Optics 2025-12-30 v1

Abstract

Dissipative Kerr solitons (DKSs) generated in high-Q microresonators driven by continuous-wave (CW) lasers provide chip-scale optical frequency combs composed of mutually coherent CW lines. However, their small mode volume makes them highly susceptible to thermal fluctuations, and the resulting thermo-refractive noise (TRN) perturbs the repetition rate frepf_{\rm rep}. Here, we experimentally demonstrate a blue-detuned DKS in a coupled-ring microresonator. By employing avoided-mode-crossing (AMX)-induced dispersion engineering at the pump mode, DKSs are generated even when the pump laser is tuned to the higher-frequency (blue) side of the resonance. In this regime, the pump laser not only seeds DKS formation but also serves as a cooling laser for the thermally sensitive pumped mode. We observe a self-cooling effect that reduces the phase noise of frepf_{\rm rep} by up to 14.5 dB, while achieving a pump-to-comb conversion efficiency as high as 37 %. These results establish blue-detuned DKSs as a thermally robust and power-efficient solution for integrated microcomb systems, eliminating the need for auxiliary lasers.

Keywords

Cite

@article{arxiv.2508.00432,
  title  = {Self-cooling, blue-detuned dissipative Kerr microresonator soliton comb},
  author = {Kenji Nishimoto and Kaoru Minoshima and Naoya Kuse},
  journal= {arXiv preprint arXiv:2508.00432},
  year   = {2025}
}