基于激光单频干涉和PTF传感融合的空气折射率测量方法  

Measurement of Air Refractive Index Method by Combining Laser SingleFrequency Interferometry with PTF Sensing

作　　者：严利平[1] 蒋剑波 楼盈天[1] 陈本永[1] 谢建东[1] Yan Liping;Jiang Jianbo;Lou Yingtian;Chen Benyong;Xie Jiandong(Laboratory of Nanometer Measurement Technology,Zhejiang SciTech University,Hangzhou 310018,Zhejiang,China)

机构地区：[1]浙江理工大学纳米测量技术实验室,浙江杭州310018

出　　处：《激光与光电子学进展》2023年第5期103-110,共8页Laser & Optoelectronics Progress

基　　金：国家自然科学基金(51875530);浙江省自然科学基金(LZ18E050003);教育部长江学者和创新团队计划(IRT_17R98)。

摘　　要：针对空气折射率测量中Edlén公式法测量精度受限于传感器精度,以及固定长度真空腔的激光干涉法条纹整周期难以确定的问题,提出了一种融合激光单频干涉和PTF传感的空气折射率测量方法。设计了基于固定长度单真空腔的正弦相位调制激光干涉空气折射率测量光路。利用低精度传感器获得的空气折射率预测值来确定干涉条纹整数,采用PGC-Arctan算法精确解调干涉信号相位来获得小数干涉条纹,实现空气折射率的大范围高精度实时测量。搭建了实验装置,开展了与Edlén公式法的空气折射率测量比对实验。实验结果显示,在12 min和1 h内,两种方法测得结果具有较好的一致性,两者偏差的标准偏差分别为1.5×10^(-8)和2.3×10^(-8),表明本文方法可应用于激光干涉精密位移测量中空气折射率的实时补偿。Aiming at the issue that the air refractive index measurement accuracy with the Edlén equation is limited by the sensors’accuracies and the integral interference fringe number is difficult to determine using laser interferometry with a length fixed vacuum cavity,an air refractive index measurement method combining laser singlefrequency interferometry and PTF sensing is proposed.We design a sinusoidal phase modulated laser singlefrequency interferometer with one lengthfixed vacuum cavity for measuring the air refractive index.A preestimated value of air refractive index is obtained to determine the integral interference fringe number using the environmental parameters obtained by the low precision sensors.Then,the PGCArctan algorithm is adopted to accurately demodulate the phase of the interference signal to obtain the fractional interference fringe.Therefore,realtime largerange and highaccuracy measurements of air refractive index can be realized.The experimental setup is built,and the measurement results of the proposed method are compared with the findings of the Edlén equation.The experimental findings show that the measurement results of the two methods are in good agreement.The standard deviations of the differences between the measurement results of the two methods in 12 min and 1 h are 1.5×10^(−8) and 2.3×10^(−8),respectively.Experimental results indicate that the proposed method can be applied to the realtime compensation of air refractive index in laser interferometric precision displacement measurement.

关 键 词：测量 空气折射率测量 激光单频干涉 Edlén公式法 正弦相位调制 

分 类 号：TH741[机械工程—光学工程]