光学学报, 2014, 34 (6): 0628001, 网络出版: 2014-05-26
基于F-P腔强度解调的微位移传感器
A Novel Fabry-Perot Micro-displacement Sensor Based on Intensity Demodulation Method
传感器 法布里珀罗干涉 微位移 强度解调 腔长锁定 sensors F-P interference micro displacement intensity demodulation cavity length lock
摘要
基于一次谐波腔长锁定技术,设计了一种基于法布里珀罗(F-P)腔干涉的强度解调型微位移传感器。系统对F-P腔的初始腔长进行动态锁定,通过将F-P腔腔长的微小变化转化为强度信号,实现直接快速地对待测目标的微位移进行测量。详细地阐述了位移传感器的理论模型及一次谐波锁定F-P腔腔长的技术方案,实验中采用商用的高精度压电陶瓷平移台(PZT)模拟了实际物体的运动状态,实验结果表明,该系统对峰峰值在λ/4(λ为光波波长)以内、频率不高于400 Hz的微位移有很好的测量结果,频率误差小于0.5 Hz,测量精度小于1 nm。
Abstract
According to the first harmonic cavity-length locking technology, a novel kind of micro-displacement sensor, which combines F-P interferometer and intensity demodulation method, has been developed. The initial length of the F-P cavity has been actively scanned and dynamically locked. And then the change of the F-P cavity-length induced by the motion of the target is coded on the variation of the optical output power of the cavity. As a consequence, a fast and direct micro-displacement sensing scheme through the intensity demodulation is available.The theoretical model of the displacement sensor and the technical scheme for actively locking the initial length of the F-P cavity through the first harmonic have been demonstrated in detail, respectively. Micro-displacement experiments provided by a commercial high-precision PZT with different vibrating parameters have been performed, and the experimental results agree well with the motion of the PZT within peak-to-peak amplitude of λ/4 and frequency is no more than 400 Hz. The frequency error is less than 0.5 Hz, and the total measurement accuracy is less than 1 nm.
李春成, 王鸣, 夏巍, 刘强, 郝辉. 基于F-P腔强度解调的微位移传感器[J]. 光学学报, 2014, 34(6): 0628001. Li Chuncheng, Wang Ming, Xia Wei, Liu Qiang, Hao Hui. A Novel Fabry-Perot Micro-displacement Sensor Based on Intensity Demodulation Method[J]. Acta Optica Sinica, 2014, 34(6): 0628001.