基于锁模激光器的FBG电流传感器高速解调系统

High Speed Demodulation System for FBG Current Sensor Based on Mode-Locked Laser

智能电网可靠、安全、经济、高效的发展目标,对电流参数的检测速率提出了更高的需求。本文开展了锁模激光器对基于磁致伸缩效应的光纤布拉格光栅(fiber Bragg grating, FBG)电流传感器复用实现高速解调的实验研究,首次将时间拉伸-色散傅里叶变换(time-stretch dispersive Fourier transformation, TS-DFT)技术与光纤电流传感技术进行了结合。固定于磁致伸缩材料表面的FBG能够感知通电螺线管产生的磁场所引发的材料应变。TS-DFT技术可将应力引起的FBG波长偏移映射为时域上反射脉冲的时延偏移实现高速解调。在0~4.5 A电流范围内对2个传感FBG的波长复用进行监测,系统的解调速率高达69.6 MHz,该技术在电流或磁场传感领域有广阔的应用前景。

The development goals of reliable,safe,economical,and efficient smart grid place higher demands on the detection rate of current parameters.This paper presents an experimental investigation of high-speed demodulation of fiber Bragg grating(FBG)current sensor,based on magnetostrictive effect and mode-locked laser multiplexing.For the first time,time-stretch dispersive Fourier transformation(TS-DFT)is combined with fiber current sensing techniques.FBG,fixed on the magnetostrictive material,detects the material strain caused by the magnetic field generated by the energized solenoid,enabling current sensing. TS-DFT maps the wavelength shift of FBG caused by stress to the time-domaindelay shift in the reflected pulse, facilitating high-speed demodulation. The wavelengthmultiplexing of the two sensing FBGs is monitored in the current range of 0 to 4.5 A,achieving a demodulation rate of up to 69.6 MHz. This method has broad applicationprospects in the field of current or magnetic field sensing.