光纤Bragg光栅水听器特性及实验研究

论述了光纤Bragg光栅（FBG）水听器探头基元 （FBG）的传感特性,分析了FBG的耦合系数、反射率、反射带宽和栅长对光纤Bragg光栅水听器传感特性的影响.通过改进光纤Bragg光栅水听器探头封装结构,增加了其压力敏感系数.并将实验结果与标准水听器（压电型）比较,标定出光纤Bragg光栅水听器的声压灵敏度；对传感信号进行电路解调,得出了解调结果,结果显示与原始声波信号基本一致.试验表明,在1 kHz~25 kHz的声波检测范围,光纤Bragg光栅水听器响应平坦度好,信号输出稳定,证明文中采取的改进措施是有效的.

Study on Characters and Experiment of FBG Hydrophone

The acoustic sensing characters of Fiber Bragg Grating (FBG) hydrophone were addressed and the relationship on FBG's sensing character and the reflection index, grating distance and reflection wavelength bandwidth of the FBG was analyzed. By improving encapsulation structure of FBG sensing-head, the acoustic sensing-index was increased. The experiment sensing result of FBG hydrophone was compared with which of standard hydrophone and response dexterous was demarcated. The sensing signal was demodulated with demodulateonal circuit and the result according with acoustic signal was obtained.The test result indicates that at the acoustic frequency of 1 kHz~30 kHz, compared with the standard piezo-acoustic hydrophone, the frequency response of the FBG hydrophone is very flat and the SNR of output signal is good. The improved measures are in effect.