Program gain and loss for broadband soliton microcombs
Abstract
Soliton microcombs provide compact, broadband, coherent light sources for precision metrology, spectroscopy, communications, and microwave photonics. Extending their spectral span while retaining useful output power remains challenging and often requires impractically high pump power. Existing approaches mainly tailor the dispersion and pumping conditions, but they do not exploit the coupling spectrum as a programmable aspect of soliton operation. Here we introduce a meta-coupler whose lithographically programmed coupling spectrum concentrates strong pump access near the pumped resonance while leaving most comb lines close to the intrinsic loss rate. SiN microresonators incorporating a meta-coupler exhibit broader circulating soliton spectra, nearly twofold larger 3 dB soliton bandwidths, up to about 12 dB higher central comb-line power, and up to about fivefold greater emitted comb power, without an additional pump-power penalty. Our work unlocks gain and loss as simultaneous programmable knobs for realizing high-performance soliton microcombs.
Cite
@article{arxiv.2604.19913,
title = {Program gain and loss for broadband soliton microcombs},
author = {Yuanlei Wang and Xinrui Luo and Binbin Nie and Du Qian and Zhenchao Mei and Yanwu Liu and Haoyang Luo and Junqi Wang and Yiwen Yang and Zu-Lei Wu and Tianxiang Hong and Bei-Bei Li and Qihuang Gong and Qi-Fan Yang},
journal= {arXiv preprint arXiv:2604.19913},
year = {2026}
}