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

Abstract

A fiber-optic Fabry-Pérot acoustic sensor with a <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex Notation="TeX">${\sim}{100}\hbox{-}{\rm nm}$</tex></formula> -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 <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">${\sim}{\rm 60}~\mu{\rm Pa}/{\rm Hz}^{1/2}$</tex></formula> 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.