Graphene diaphragm-based extrinsic Fabry-Perot interferometer for low frequency acoustic sensing

Abstract

A low frequency fiber acoustic sensor based on the transduction of 10nm thickness graphene diaphragm has been experimentally demonstrated. The ultra thin graphene diaphragm is used as a reflecting surface to form an extrinsic Fabry-Perot interferometer. The diameter of the graphene diaphragm is selected as 125 pm, thus the resonant frequency of 25958Hz is obtained. The sensitivity of the acoustic pressure can be as high as 43.5dB re 1 V/Pa@60Hz. Moreover, the minimum detectable acoustic pressure of 171.6pPa/Hz1/2@60Hz is achieved. The compact structure, simple manufacture and low cost fiber acoustic sensor can be realized.