Chen Ke, Yang Beilei, Deng Hong, Guo Min, Zhang Bo, Yang Yang, Liu Shuai, Zhao Yaming, Peng Wei, Yu Qingxu
Opt Express. 2020 May 11;28(10):15050-15061. doi: 10.1364/OE.387195.
A Fabry-Perot (F-P) interferometric fiber-optic cantilever sensor is presented for simultaneous measurement of acoustic pressure and temperature, which are demodulated by a single high-speed spectrometer. The acoustic pressure wave pushes the cantilever to produce periodic deflection, while the temperature deforms the sensor and causes the F-P cavity length to change slowly. The absolute length of the F-P cavity of the fiber-optic cantilever sensor is calculated rapidly by using a spectral demodulation method. The acoustic pressure and temperature are obtained by high-pass filtering and averaging the continuously measured absolute cavity length value, respectively. The experimental results show that the acoustic pressure can be detected with an ultra-high sensitivity of 198.3 nm/Pa at 1 kHz. In addition, an increase in temperature reduces the resonant frequency of the acoustic response and increases the static F-P cavity length. The temperature coefficient of the resonance frequency shift and the temperature response of the sensor are -0.49 Hz/°C and 83 nm/°C, respectively. Furthermore, through temperature compensation, the measurement error of acoustic pressure reaches ± 3%. The proposed dual parameter measurement scheme greatly simplifies the system structure and reduces the system cost.
提出了一种法布里-珀罗（F-P）干涉型光纤悬臂梁传感器，用于同时测量声压和温度，由单个高速光谱仪进行解调。声压波推动悬臂梁产生周期性偏转，而温度使传感器变形并导致F-P腔长度缓慢变化。采用光谱解调方法快速计算光纤悬臂梁传感器F-P腔的绝对长度。分别通过高通滤波和对连续测量的绝对腔长度值求平均来获得声压和温度。实验结果表明，在1 kHz时，该传感器能够以198.3 nm/Pa的超高灵敏度检测声压。此外，温度升高会降低声学响应的共振频率，并增加静态F-P腔长度。共振频率偏移的温度系数和传感器的温度响应分别为-0.49 Hz/°C和83 nm/°C。此外，通过温度补偿，声压测量误差达到±3%。所提出的双参数测量方案大大简化了系统结构并降低了系统成本。
