Fabry-Perot Interference Fiber Acoustic Wave Sensor Based on Laser Welding All-Silica Glass

Materials

Wenhua Wang¹ 

[1] School of Electronic and Information Engineering, Guangdong Ocean University, Zhanjiang 524088, China;

关键词: optical fiber acoustic wave sensor;    sensor probe;    Fabry–Perot interferometer;    laser welding;    silica glass;   

DOI  :  10.3390/ma15072484

来源: DOAJ

【 摘 要 】

Due to the small difference between the thermal expansion coefficients of silica optical fiber and silica glass, they are used as probe materials of optical fiber acoustic wave sensors. According to the light absorption characteristics of a pressure-sensitive silica diaphragm and silica glass, the laser welding of an all-silica Fabry–Perot (FP) interference optical fiber acoustic wave sensor with a CO₂ laser is proposed. For understanding the influence of thermal expansion of sealing air in an FP cavity and the drift of interference-intensity demodulation working point of a FP interference acoustic wave sensor, we designed a process for the laser welding of an ultra-thin silica diaphragm and sleeve and optical fiber and sleeve. The exhaust hole of the FP cavity is reserved in the preparation process, and an amplified spontaneous emission light source and a tunable optical-fiber FP filter are introduced to stabilize the working point. The sensor is tested with a 40 kHz sound vibration signal. The results show that the sound pressure sensitivity of the sensor to an acoustic source of 0.02–0.1 W/cm² is 6.59 mV/kPa. The linearity coefficient is 0.99975, indicating good linearity.

【 授权许可】

Unknown