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arXiv · 2508.00432

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

Kenji Nishimoto·Kaoru Minoshima·Naoya Kuse
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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 $f_{\rm rep}$. 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 $f_{\rm rep}$ 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.

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Kenji Nishimoto, Kaoru Minoshima, Naoya Kuse. 2025-08-01. Self-cooling, blue-detuned dissipative Kerr microresonator soliton comb. https://doi.org/10.1063/5.0294122

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