Rhythmic soliton interactions for integrated dual-microcomb spectroscopy
Abstract
Rotation symmetry of microresonators supports the generation of phase-locked counter-propagating (CP) solitons that can potentially miniaturize dual-comb systems. Realization of these dual-comb compatible solitons in photonic integrated circuits remains a challenge. Here, we synthesized such CP solitons in an integrated silicon nitride microresonator and observed forced soliton oscillation due to rhythmic, time-varying soliton interactions. The interactions result in seconds mutual-coherence passively. Temporal motion in the soliton streams is discerned by measuring a quadratic-scaling frequency noise peaks and an inverse quadratic-scaling microcomb sidebands. By generating a CP soliton trimer to have two synchronized solitons in one of the orbiting directions, we resolve the incapability of measuring two unsynchronized CP soliton dimer pulses by optical cross-correlation, and show CP solitons undergo complex motion trajectory. We further prove that precise dual-comb spectroscopy with an acquisition time as short as 0.6 s is feasible using these solitons, although the temporal motion limits the dynamic range. Besides revealing soliton interactions with different group velocities, our work propels the realization of photonic integrated dual-comb spectrometers with high passive coherence.
Cite
@article{arxiv.2402.08432,
title = {Rhythmic soliton interactions for integrated dual-microcomb spectroscopy},
author = {Zihao Wang and Yifei Wang and Baoqi Shi and Chen Shen and Wei Sun and Yulei Ding and Changxi Yang and Junqiu Liu and Chengying Bao},
journal= {arXiv preprint arXiv:2402.08432},
year = {2025}
}