激光合成波长干涉测量空气折射率的方法研究

项目名称： 激光合成波长干涉测量空气折射率的方法研究

项目编号： No.51475435

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 机械、仪表工业

项目作者： 严利平

作者单位： 浙江理工大学

项目金额： 83万元

中文摘要： 空气折射率的检测与校准是以激光波长为长度基准的精密测量方法的基础测量问题。现有的空气折射率测量方法中，基于PTF传感的Edlén法受传感器精度和公式本身不确定度的限制，干涉测量法则受条纹有效细分和一阶非线性误差的影响，测量精度都难以提高。本项目拟通过空气折射率传感原理的创新，将难以测量的空气折射率微小变化量转化为易于检测的毫米或微米级位移测量，提出一种激光合成波长干涉测量空气折射率的新方法，可实现高精度的空气折射率绝对测量。通过对该测量方法的理论分析、测量系统的设计与优化、测量装置的构建和实验验证等，研究空气折射率测量误差的形成机理和影响因素及其补偿方法，解决真空腔变形或运动对空气折射率测量精度影响的关键技术，研制一套高精度的新型空气折射率测试计量装置。通过本项目的研究，旨在为精密长度测量领域相关科学研究提供精确的空气折射率测量方法和测试计量仪器，拟实现空气折射率测量不确定度为1E-9。

中文关键词： 空气折射率；合成波长干涉；相位检测；纳米测量；测量不确定度

英文摘要： For the precision measurement methods which adopt the laser wavelength as the length standard, the measurement and calibration of air refractive index is a fundamental measurement problem. Among the existing air refractive index measurement methods, the Edlén equation method based on pressure, temperature and humidity (PTF) sensing is limited by the accuracy of environmental parameter sensors and the uncertainty of equation itself, whereas the laser interferometry is affected by the effective subdivision of interference fringe and the first-order nonlinearity error, so the measurement accuracy of air refractive index is difficult to improve. In this project, a novel air refractive index measurement method based on the laser synthetic wavelength interferometry is proposed. By innovating the air refractive index sensing principle, a slight air refractive index fluctuation is magnified to a large displacement on the order of millimeter or micrometer. Therefore high precision absolute measurement of air refractive index is realized. Through the theoretical analysis of the measurement method, optimization design of the measurement system, construction of experimental setup and experimental verification, the formation mechanism, influencing factors and compensation method of measurement error of air refractive index will be studied systematically. The effects on the air refractive index measurement accuracy induced by the vacuum cavity deformation or movement will be solved. And a novel air refractive index measurement system with high accuracy will be developed. Through the study of this project, the aim is to provide an accuracy air refractive index measurement method and test or metrology instrument for scientific researches related to precision length measurement.

英文关键词： Refractive index of air;Synthetic wavelength interferometry;Phase detection;Nanometer diasplacement measurement;Measurement uncertainty