文档介绍：纳米级分辨率双频激光回馈位移测量系统*
张立1 周鲁飞2 谈宜东2 张书练2
(1. 北京交通大学理学院, 北京100044; 2. 清华大学精密测试技术及仪器国家重点实验室, 北京100086)
摘要: 提出了一种基于双频激光回馈原理的高精度位移测量方法。在分析双频激光回馈测量原理的基础上, 研究了双频激光回馈的基本现象并给出了理论依据, 进一步的在回馈光学系统基础上, 对两路正交的光回馈条纹利用电路进行细分处理: 即四倍频细分产生大数计数及在一个大数脉冲内再进行小数细分, 最后再将二者相结合。主要采用可编程逻辑器件FPGA和单片机设计信号处理电路, 四倍频细分主要利用FPGA实现, 小数部分主要通过单片机软件查表程序实现。全部电路并通过逻辑、时序仿真, 验证了本方法的可行性。目前此系统满足高精度位移测量的要求。
关键词: 双频激光; 位移测量; 光回馈; 细分电路
中图分类号: TB92 文献标识码: A 国家标准学科分类代码:
Dual-frequency laser optical feedback displacement measurement
system with nanometer resolution
Zhang Li1 Zhou Lufei2 Tan Yidong2 Zhang Shulian2
(1. School of Science, Beijing Jiaotong University Beijing 100044, China;
2. The State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision
Instruments, Tsinghua University, Beijing 100086, China)
Abstract: A nanometer-resolution displacement measurement system based on weak feedback effect of birefringent dual-frequency laser has been presented and demonstrated. The experimental setup of an optical feedback dual-frequency laser is developed by using the phase delay between the optical feedback fringes of two orthogonally polarized lights to realize displacement division and direction discrimination. A concise theory is given to explain this experimental result. The sub-circuit is posed of the FPGA and the MCU. The FPGA is used to realize the division of big numb