介绍了一种基于DBR光纤激光传感器同时测量超声与温度的双参量测量方法。通过对光纤DBR激光传感器中,由双折射效应产生的两种非简并偏振模式拍频的调制,同时获得温度与超声的测量信息。文中首先基于DBR光纤激光传感器偏振外差技术测量的基本理论,分析其在温度信号调制和超声信号调制下的测量原理。然后,设计温度与超声测量实验,得到不同温度下DBR光纤激光传感器的频谱输出,以及同一温度下(34.9℃),两种超声信号(5 MHz和7 MHz)的频率调制输出。最后,实验论证了不同超声信号在不同温度下的双参量测量输出。本文通过理论与实验的对比分析,表明了DBR光纤激光传感器在超声信号测量的同时,还可以实现温度信号的测量,10 MHz以内温度灵敏度均值0.116 MHz/℃。
This paper presents a dual-parameter measurement method using fiber laser sensor of simultaneously measuring ultrasound and temperature,which is based on the modulation of two nearly degenerate polarization modes produced by birefringence effect. The measuring principle of DBR(Distributed-Bragg-Reflector)fiber laser sensor under the modulation of temperature signal and ultrasonic signal was analysed. The measurement experiment of temperature and ultrasound was designed. The spectrum of the output beat frequency signals at different tempera?tures and the frequency modulation of ultrasonic with the signal of 5 MHz,7 MHz at 34.9℃was achieved. The out?put of dual-parameter measurement in different ultrasonic signal and temperature was verified by experiment. The experimental results show that the DBR fiber laser sensor have ability of measuring the ultrasound with temperature signal together. The average of temperature sensitivity is 0.116 MHz/℃within 10 MHz.