基于氮化硅膜片的光纤法布里-珀罗声波传感器  

Silicon Nitride Membrane-Based Fiber-Optic Fabry-Perot Acoustic Sensor

作　　者：丁武成 魏鹤鸣 韦妍 朱梦实 张亮 庞拂飞[1] Ding Wucheng;Wei Heming;Wei Yan;Zhu Mengshi;Zhang Liang;Pang Fufei(Key Laboratory of Specialty Fiber Optics and Optical Access Networks,Joint International Research Laboratory of Specialty Fiber Optics and Advanced Communication,School of Communication&Information Engineering,Shanghai University,Shanghai 200444,China)

机构地区：[1]上海大学通信与信息工程学院特种光纤与光接入网省部共建国家重点实验室培育基地,特种光纤与先进通信国际合作联合实验室,上海200444

出　　处：《光学学报》2025年第2期153-160,共8页Acta Optica Sinica

基　　金：国家自然科学基金(62005153)。

摘　　要：研制了一种基于氮化硅方形膜片的光纤法布里-珀罗(FP)声波传感器,采用硅基微机电系统(MEMS)工艺分别制备了厚度为30 nm和50 nm的氮化硅窗口型振膜,并进一步封装成光纤FP微腔并用于声波探测。由于声波引起膜片振动,从而引起FP干涉光的相位或光谱偏移,通过测量这种偏移量可获取声波的幅频特性。实验结果表明,两种传感器在声波频率为1~20 kHz范围内具有较好的频谱响应,其中膜厚为50 nm的传感器共振频率约为16.5 kHz,其声压灵敏度为60.175 mV/Pa@16.5 kHz,最小可检测压力为2.57μPa/Hz^(1/2)@16.5 kHz。可见,所设计的光纤声波传感器具有较高的灵敏度和出色的声波检测性能,在水下目标探测等领域具有广阔的应用前景。Objective As one of the earliest natural phenomena to be studied,sound waves carry abundant information and energy.Acoustic sensors play a key role in fields such as fire safety,structural health monitoring,extreme environment communication,smart grid security detection,and medical imaging.With the rapid development of information technology,the demand for high-sensitivity and wide-bandwidth acoustic signal detection has increased.Recently,the research focus in acoustic sensing has shifted from electroacoustic to photoacoustic technology.Compared to electroacoustic sensors,fiber-optic acoustic sensors offer advantages such as high sensitivity,wide dynamic range,fast response,and excellent anti-electromagnetic interference performance.As these sensors are made from non-metallic,insulating materials,they are suitable for environments where electroacoustic sensors may fail,including those with strong electromagnetic interference,flammable or explosive conditions,and high temperatures or pressures.Methods The fiber-optic Fabry-Perot(FP)interferometer integrates optical elements into the fiber,retaining the high sensitivity and precision of traditional FP interferometers,while overcoming the challenges of size and environmental sensitivity.The fiber-optic acoustic sensor uses a double-reflector setup to create the FP cavity,leveraging the diaphragm’s simple structure,ease of fabrication,and high sensitivity.When an external sound pressure signal affects the diaphragm,it induces slight deformation,altering the length of the FP cavity,which in turn causes fluctuations in the interference spectrum and changes in the intensity and phase of the reflected light.Detailed information about the external acoustic signal can be derived by detecting these changes.The material and structure of the diaphragm are crucial to the performance of the FP cavity.Silicon nitride membranes,known for their high mechanical stiffness and superior elasticity,offer highly sensitive responses to vibrations caused by small sound waves and can ef

关 键 词：法布里-珀罗干涉仪 声波传感器 氮化硅 MEMS 

分 类 号：O436[机械工程—光学工程]