Fiber-Optic Fabry–Pérot Acoustic Sensor With Multilayer Graphene Diaphragm

A fiber-optic Fabry-Pérot acoustic sensor with a ${\sim}{100}\hbox{-}{\rm nm}$ -thick multilayer graphene diaphragm is reported. Acoustic testing demonstrates a pressure-induced deflection of 1100 nm/kPa and a noise equivalent acoustic signal level of ${\sim}{\rm 60}~\mu{\rm Pa}/{\rm Hz}^{1/2}$ at the frequency of 10 kHz. The sensor exhibits a flat frequency response from 0.2 to 22 kHz and may be useful for highly sensitive acoustic sensing.