Miniaturized and highly sensitive fiber-optic Fabry–Perot sensor for mHz infrasound detection  

作　　者：PEIJIE WANG YUFENG PAN JIANGSHAN ZHANG JIE ZHAI DEMING LIU PING LU 

机构地区：[1]Wuhan National Laboratory for Optoelectronics(WNLO)and National Engineering Research Center of Next Generation Internet Access System,School of Optical and Electronic Information,Huazhong University of Science and Technology,Wuhan 430074,China [2]Optics Valley Laboratory,Wuhan 430074,China [3]Department of Electronics and Information Engineering,Huazhong University of Science and Technology,Wuhan 430074,China

出　　处：《Photonics Research》2024年第5期969-978,共10页光子学研究（英文版）

基　　金：Science Fund for Creative Research Groups of the Nature Science Foundation of Hubei(2021CFA033);National Natural Science Foundation of China(62275096);Interdisciplinary Research Program(HUST:2023JCYJ046)。

摘　　要：Infrasound detection is important in natural disasters monitoring,military defense,underwater acoustic detection,and other domains.Fiber-optic Fabry–Perot(FP)acoustic sensors have the advantages of small structure size,long-distance detection,immunity to electromagnetic interference,and so on.The size of an FP sensor depends on the transducer diaphragm size and the back cavity volume.However,a small transducer diaphragm size means a low sensitivity.Moreover,a small back cavity volume will increase the low cut-off frequency of the sensor.Hence,it is difficult for fiber-optic FP infrasound sensors to simultaneously achieve miniaturization,high sensitivity,and extremely low detectable frequency.In this work,we proposed and demonstrated a miniaturized and highly sensitive fiber-optic FP sensor for m Hz infrasound detection by exploiting a Cr-Ag-Au composite acoustic-optic transducer diaphragm and a MEMS technique-based spiral micro-flow hole.The use of the spiral micro-flow hole as the connecting hole greatly reduced the volume of the sensor and decreased the low-frequency limit,while the back cavity volume was not increased.Combined with the Cr-Ag-Au composite diaphragm,a detection sensitivity of-123.19 dB re 1 rad∕μPa at 5 Hz and a minimum detectable pressure(MDP)of1.2 mPa∕Hz^(1∕2)at 5 Hz were achieved.The low detectable frequency can reach 0.01 Hz and the flat response range was 0.01–2500 Hz with a sensitivity fluctuation of±1.5 d B.Moreover,the size of the designed sensor was only 12 mm×Φ12.7 mm.These excellent characteristics make the sensor have great practical application prospects.

关 键 词：SOUND fiber CAVITY 

分 类 号：TP212[自动化与计算机技术—检测技术与自动化装置]