High-power, low-noise Brillouin laser on a silicon chip

Yingchun Qin, Nanjing University
Shulin Ding, Nanjing University
Menghua Zhang, Nanjing University
Jianming Wen, Kennesaw State University


We realize a chip-based Brillouin microlaser with remarkable features of high power and lownoise using a microtoroid resonator. Our Brillouin microlaser is able to output a power of up to 126mW with a fundamental linewidth down to 245 mHz. Additionally, in the course of Brillouin lasing we observe an intriguing power saturation-like effect, which can be attributed to complex thermo-optic-effect-induced mode mismatch between the pump and Brillouin modes. To have a quantitative understanding of this phenomenon, we develop a model by simultaneously considering Brillouin lasing and the thermo-optic effect occurring in the microcavity. Of importance, our theoretical results matchwell with experimentally measured data.