A multi-frequency fiber optic acoustic sensor (FOAS) based on graphene-oxide Fabry-Perot microcavity (GO-FPM) is proposed and demonstrated. The micrometer-size FP cavity is formed by a single-mode-fiber end surface and a layer of GO diaphragm. The GO diaphragm is used as the acoustic sensitive diaphragm to realize the acoustic signal detection. The performance of the GO-FPM FOAS for single-frequency, dual-frequency and triple-frequency acoustic signal detection is experimentally investigated. The influence of the input optical power and wavelength on sensor performance is also investigated. As for single-frequency acoustic signal detection, the signal to noise ratio (SNR) can be as high as 65.2 dB, with a broad frequency response ranged from 400 Hz to 20 kHz and a high linearity of ≈1. The SNRs for the dual-frequency and the triple-frequency acoustic signal detection can be >65.1 dB and >61.8 dB, respectively. The proposed GO-FPM FOAS have potential applications in structural health monitoring, fiber hydrophone, pipeline leakage detection, biomedicine, etc.

提出并演示了一种基于氧化石墨烯法布里-珀罗微腔 (GO-FPM) 的多频光纤声学传感器 (FOAS)。微米级FP腔由单模光纤端面和一层GO膜片构成。GO振膜作为声敏振膜实现声信号检测。实验研究了 GO-FPM FOAS 在单频、双频和三频声学信号检测中的性能。还研究了输入光功率和波长对传感器性能的影响。对于单频声学信号检测，信噪比（SNR）可高达65.2 dB，具有400 Hz至20 kHz的宽频响应范围和≈1的高线性度。双频和三频声信号检测的信噪比可以分别 >65.1 dB 和 >61.8 dB。所提出的 GO-FPM FOAS 在结构健康监测、光纤水听器、管道泄漏检测、生物医学等方面具有潜在应用。