Broadband tuning of the optical and mechanical modes in hollow bottle-like microresonators

In this paper, we report the mechanical tuning of the optical and mechanical modes in the hollow bottle-like microresonator (BLMR). The optical modes with a quality factor of 1.55 × 10⁸ and mechanical modes with a quality factor of 2.5 × 10³ were demonstrated in such microresonators. By stretching the microresonator, the optical modes can be tuned over one free spectral range, as large as 917 GHz (~ 7.3 nm). Meanwhile, the range of frequency tuning of mechanical modes can be as large as 1 MHz, which is about 2.9% of the mode frequency. This effective approach to tune the optomechanical cavity can be used for the tunable photon-phonon conversion and the synchronization of mechanical oscillators in separated optomechanical systems.