Suppression of phonon tunneling losses by microfiber strings for high-Q membrane microresonators

摘要

We propose to utilize a microfiber string to isolate the tunneling of acoustic waves between a membrane frame and its holder. The displacement response of the membrane frame with and without the vibration isolation is characterized using an optical interferometer. A displacement power suppression of 40 dB is achieved around the fundamental mode frequency of the membrane. We demonstrate that the Q factor of a SiN membrane microresonator with our vibration isolation method can reach 1.78×10~6 in room temperature.