基于线阵扫描的FBG高温传感解调系统

FBG high temperature sensor demodulation system based on linear array scanning

为了实现光纤布拉格光栅温度传感的高速解调,建立基于线阵分光扫描法的解调系统。该系统通过SLD宽带光源、线阵InGaAs探测阵列以及FPGA控制芯片实现高速解调。基于FPGA控制芯片,完成探测单元及采样单元电路设计,并给出系统实施方案。采用飞秒激光制备的聚酰亚胺涂层的纯石英光纤布拉格光栅传感器搭建高温传感系统,对于传感信号进行高斯拟合实现寻峰。该解调系统无机械扫描部件,可实现光纤布拉格光栅的高速解调,波长解调范围为1 500 nm~1 650 nm,扫描频率为17 kHz,波长分辨率为7 pm,温度分辨率小于1℃。

In order to realize the high-speed demodulation of the fiber Bragg grating temperature sensor,a demodulation system based on the linear-array spectroscopic scanning method is established. The system achieves high-speed demodulation by using SLD broadband light source,linear InGaAs detection array and FPGA control chip. Based on the FPGA control chip,complete the circuit design of the detection unit and the sampling unit,and give the system implementation plan. A pure silica fiber Bragg grating sensor with a polyimide coating prepared by a femtosecond laser is used to build a high temperature sensing system,and Gaussian fitting is performed on the sensing signal to achieve peak finding. The demodulation system has no mechanical scanning components and can realize high-speed demodulation of fiber Bragg gratings. The wavelength demodulation range is 1 500 nm ~ 1 650 nm,the scanning frequency is 17 kHz,the wavelength resolution is 7 pm,and the temperature resolution is less than 1 ℃ .