OFDR Based Distributed Temperature Sensor Using the Three-Channel Simultaneous Radio-Frequency Lock-ln Technique

• 作者: Ke CHEN Xinlei ZHOU Wei PENG Qingxu YU
• 来源期刊: 光子传感器:英文版
• 学科: 工学
• 关键词: 分布式温度传感器 锁定放大器 混合技术 三通道 射频 现场可编程门阵列 弱信号检测 测量时间
• 年，卷（期）: 2015,（3）
• 页码范围: 217-223
• 页数: 7页
• 分类号: TN722
• 语种: 中文

摘要

Weak signal detection for single-mode fiber-optic distributed temperature sensor (DTS) is a key technology to achieve better performance. A hybrid technique combining the incoherent optical frequency domain reflectometry (IOFDR) and the three-channel simultaneous radio-frequency (RF) lock-in amplifier (LIA) is presented to improve the signal-to-noise ratio (SNR) of the measured spontaneous Raman backscattered light. The field programmable gate array (FPGA) based RF-LIA is designed with a novel and simple structure. The measurement frequency range is achieved from 1 kHz to 100 MHz. Experimental results show that the backscattered light signal of picowatt level can be detected with high SNR. With a 2.5kin single-mode fiber, a 1064nm laser source, and the measurement time of 500 s, this sensing system can reach a spatial resolution of 0.93 m and a temperature resolution of about 0.2℃.