Soliton microcombs in X-cut LiNbO3 microresonators

• DOI: 10.48550/arxiv.2502.07180
• Publication Date: 2025-02-10
• Authors: Binbin Nie; Xiaomin Lv; Chen Yang; Rui Ma; Kaixuan Zhu; Ze Wang; Yanwu Liu; Zhenyu Xie; Xing Jin; Guanyu Zhang; Qian Du; Zhenyu Chen; Qiang Luo; Shuting Kang; Guowei Lv; Qihuang Gong; Bo Fang; Qifan Yang
• Keywords: FOS: Physical sciences; Physics - Optics; Optics (physics.optics)

Chip-scale integration of optical frequency combs, particularly soliton microcombs, enables miniaturized instrumentation for timekeeping, ranging, and spectroscopy. Although microcombs have been demonstrated on various material platforms, realizing complete comb functionality photonic chips requires the co-integration high-speed modulators efficient doublers, features that are available in a monolithic form X-cut thin-film lithium niobate (TFLN). However, pronounced Raman nonlinearity associated with extraordinary light this platform has so far precluded microcomb generation. Here, we report generation transverse-electric-polarized 25 GHz repetition rate high-Q microresonators TFLN chips. By precisely orienting racetrack microresonator relative to axis, mitigate enable formation under continuous-wave laser pumping. Moreover, spectra extended 350 nm pulsed This work expands capabilities photonics paves way fast-tunable, self-referenced microcombs.