Michelson干涉型光纤弱磁场传感器信号检测电路研究

Detection Electronics of Magnetic Sensor Based on Michelson Interferometer

针对Michelson光纤弱磁场传感器的特点,设计和实现了控制和信号检测系统。着重对传感器信号检测部分的电路进行了分析和研究,采用了相位自跟踪锁定放大技术进行微弱信号检测;针对磁致伸缩材料的非线性响应特点,设计了定偏闭环反馈系统,使探头始终工作在最佳偏置磁场下。经实验验证,系统灵敏度高,抑制噪声能力强。

According to the features of the magnetic sensor based on Michelson interferometer, the control and detection electronics are designed and implemented. Some key techniques for the detection electronics, including weak signal detection employing self phase- tracking lock-in amplifier, are analyzed. The negative feedback system with fixed bias is designed based on nonlinear response of the magnetostrictive materials so as to keep the sensor work at its most sensitive situation. Experimental results show that the system has high sensitivity and good ability to suppress noise.