An air-pressure and acoustic fiber sensor based on graphene-oxide Fabry-Perot interferometer

• A fiber optic sensor for air-pressure and acoustic detection based on graphene-oxide Fabry-Perot interferometer. • The sensitivities for air-pressure and acoustic detection are 3.81 nm/kPa and 0.102 V/mPa@20 kHz. • Single- and multi-frequency acoustic signal can be detected both in air and underwater, with noise-limited MDP of 28.74 µPa/Hz 1/2 @20 kHz and 14.44 µPa/Hz 1/2 @13 kHz. • The proposed multi-parameter sensor has potential applications in structure health and vibration monitoring. A fibre optic sensor for both air-pressure and acoustic signal detection based on graphene-oxide Fabry-Perot interferometer (GO-FPI) is proposed and demonstrated. The GO-FPI consists of a cleaved single-mode fibre (SMF) and GO film with good uniformity and high surface evenness. As for air-pressure detection, the highest sensitivity is 3.81 nm/kPa. As for acoustic sensing, the frequency response ranges from 4 Hz to 20 kHz with good fidelity and extremely high linearity of ∼ 1, with capability of single-frequency and multi-frequency signal detection. Moreover, the GO-FPI can detect the acoustic signal both in air and underwater with high stability. The noise-limited minimum detectable pressure levels are 28.74 µPa/Hz 1/2 @20 kHz in air and 14.44 µPa/Hz 1/2 @13 kHz underwater. The proposed multi-parameter sensor with high compactness and stability has potential applications in structure health and vibration monitoring.