Brillouin cavity optomechanics sensing with enhanced dynamical backactionPhotonics Research
- Guo-Qing Qin, Min Wang, Jingwei Wen, Dong Ruan, and Gui Lu Long
- received 07/09/2019; accepted 10/17/2019; posted 10/18/2019; Doc. ID 371841
- Abstract: Based on the dispersive interaction between a high quality factor (Q) microcavity and nano-objects, whispering gallery mode (WGM) microcavities have been widely used in highly sensitive sensing. Here, we propose a novel method to enhance the sensitivity of the optical frequency shift and reduce the impact of the laser frequency noise on the detection resolution through the Brillouin cavity optomechanics in a parity-time (PT ) symmetric system. The three modes interaction is sensitive to the perturbation of optical modes around the exceptional point. By monitoring the shift of the mechanical frequency, the detection sensitivity for the optical frequency shift is enhanced by 2 orders of magnitude compared with conventional approaches. We find the optical spring effect is robust to the laser frequency noise around the exceptional point, which can reduce the detection limitation caused by the laser frequency instability. Thus our method can improve the sensing ability for nano-particle sensing and other techniques based on the frequency shift of the optical mode.