Micro- and nanomechanical resonators have emerged as promising platforms for sensing a broad range of physical properties, such as mass, force, torque, magnetic field, and acceleration. The sensing performance relies critically on the motional mass, mechanical frequency, and linewidth of the mechanical resonator. Herein, we demonstrate a hetero optomechanical crystal (OMC) cavity based on a silicon nanobeam structure. The cavity supports phonon lasing in a fundamental mechanical mode with a frequency of 5.91 GHz, an effective mass of 116 fg, and a mechanical linewidth narrowing in the range from 3.3 MHz to 5.2 kHz, while the optomechanical coupling rate is as high as 1.9 MHz. With this phonon laser, on-chip sensing can be predicted with a resolution of
Kaiyu Cui, Zhilei Huang, Ning Wu, Qiancheng Xu, Fei Pan, Jian Xiong, Xue Feng, Fang Liu, Wei Zhang, Yidong Huang. Phonon lasing in a hetero optomechanical crystal cavity[J]. Photonics Research, 2021, 9(6): 937