皮米量级微位移信号处理分辨力的光纤布拉格光栅探针系统

Fiber Bragg grating probe system with picometer-level micro-displacement signal processing resolution

为了实现超高分辨力的微位移测量,建立了基于光纤布拉格光栅传感的高灵敏度探针系统,研究了静态锁相放大技术,用于检测小于纳米量级的微位移信号。根据光纤布拉格光栅传感原理,设计了高灵敏度的双光栅自补偿解调系统结构。基于信号特征研究了静态锁相放大技术,用于实时检测处理微弱测量信号。最后,通过探针系统的性能测试实验可获得灵敏度和分辨力等参数。实验结果表明:探针系统在接触区域的微位移测量范围约为1μm,灵敏度为-15.33 mV/nm,短期噪声极差的均值为0.83 mV,标准差为0.32 mV,信号处理分辨力约为0.06 nm(60 pm),其标准差为0.02 nm(20 pm)。该系统采用光纤布拉格光栅传感技术达到了皮米量级的微位移信号处理分辨力,满足微纳测量系统的抗干扰性强、重复性好等要求,且系统成本较低。

To measure micro-displacement with ultra-high resolution,a high sensitivity probe system based on fiber Bragg grating(FBG)sensing was established and static phase-locked amplification was studied.According to the principle of FBG sensing,the structure of a dual grating self-compensating demodulation system was designed for high sensitivity.Then,based on the signal characteristics,the static phaselocked amplification technique was studied for real-time detection and processing of weak measurement signals.Finally,the system performance parameters including sensitivity and resolution were obtained through the performance experiment.The experimental results show that the micro-displacement measurement range of the probe system in the contact region is approximately 1μm,the sensitivity is-15.33mV/nm,the mean value of the short-term noise range is 0.83 mV,the standard deviation is 0.32 mV,the signal processing resolution is approximately 0.06 nm(60 pm),and the standard deviation is 0.02 nm(20 pm).Hence,the micro-displacement signal processing resolution of this FBG system reaches the picometer level.In addition,the system meets the requirements of strong anti-interference,good repeatability,and low cost.