Low-loss compact chalcogenide microresonators for efficient stimulated Brillouin lasers

作者：Yufei Li, Di Xia, Huanjie Cheng, Liyang Luo, Lin-Yi Wang, Siqing Zeng, Shuixian Yang, Linze Li, Baile Chen, Bin Zhang, Zhaohui Li · 发表于：Optics Letters · 年份：2024 · DOI：10.1364/ol.534233 · 被引用次数：10 · 研究领域：Advanced Fiber Laser Technologies、Photonic and Optical Devices、Photorefractive and Nonlinear Optics

Chalcogenide glasses (ChGs) possess a high elasto-optic coefficient, making them ideal for applications in microwave photonics and narrow-linewidth lasers based on stimulated Brillouin scattering (SBS). However, current As 2 S 3 -based integrated devices suffer from poor stability and low laser-induced damage threshold, and planar ChG devices feature limited quality factors. In this Letter, we propose and demonstrate a high-quality integrated GeSbS ChG Brillouin photonic device. By introducing Euler bending structures, we suppress high-order optical modes and reduce propagation losses in a finger-shaped GeSbS microresonator, resulting in a compact footprint of 3.8 mm 2 and a high intrinsic quality factor of 5.19 × 10 6 . The combination of GeSbS material’s high Brillouin gain and the resonator’s high-quality factor enables the generation of stimulated Brillouin lasers with a low threshold of 0.96 mW and a fundamental linewidth of 58 Hz. Moreover, cascaded stimulated Brillouin lasers can be realized up to the seventh order, yielding microwave beat frequencies up to 40 GHz.