飞秒脉冲非对称互相关绝对测距  

Absolute distance measurement based on asymmetric cross-correlation of femtosecond pulse

作　　者：彭博 曲兴华[1] 张福民[1] 张天宇 张铁犁[2] 刘晓旭[2] 谢阳 Peng Bo;Qu Xing-Hua;Zhang Fu-Min;Zhang Tian-Yu;Zhang Tie-Li;Liu Xiao-Xu;Xie Yang(State Key Laboratory of Precision Measurement Technology and Instruments,Tianjin University,Tianjin 300072,China;Beijing Aerospace Institute for Metrology and Measurement Technology,Beijing 100076,China)

机构地区：[1]天津大学精密测试技术及仪器国家重点实验室,天津300072 [2]北京航天计量测试技术研究所,北京100076

出　　处：《物理学报》2018年第21期82-87,共6页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:51675380);航天一院高校联合创新基金资助的课题~~

摘　　要：光学频率梳是一种重复频率与偏置频率锁定的新型光源,在频域上为频率间隔稳定的频率梳齿,在时域上为相对距离稳定的飞秒脉冲激光.光学频率梳在测距中的应用广泛,能够实现远距离高精度的测量.本实验使用飞秒激光脉冲作为光源,基于谐振腔扫描光学采样测距原理得到非对称的互相关干涉条纹,实现了远距离高精度的绝对测距.非对称互相关条纹可通过色散补偿与调节光学频率梳的重复频率得到,并通过得到的非对称的互相关干涉条纹对测距结果进行补偿.实验结果表明测距系统能够实现在50 m范围内误差为2μm的绝对测距,测量相对误差为1.9×10^(-7).Optical frequency comb is a kind of new pulse source, whose repetition rate and phase are locked. Optical frequency comb plays an important role in absolute distance measurement and time-frequency metrology. Lots of laser ranging methods such as time-of-flight and multi-heterodyne interferometry based on femtosecond laser pulse have been used in distance measurement. In this paper, a high-precision distance measurement system based on optical sampling by cavity tuning is set up to realize a long absolute distance measurement. And a kind of error compensation method is proposed based on the asymmetric cross-correlation patterns. In traditional optical sampling by cavity tuning measurement system, the fiber link is inserted into the reference path to extend the non-ambiguity distance, which does not have a good performance in arbitrary distance measurement. In our system, we use a 116-meter-long fiber which is inserted into the measuring path to extend the non-ambiguity distance. Besides, dispersion compensation technique is used to control the shape of the laser pulse. An asymmetric optical pulse is used as the light source, so that we can obtain extremely asymmetric cross-correlation patterns. The cross-correlation patterns can be acquired by sweeping the repetition frequency. We use an arbitrary waveform generator to provide the scanning voltage, and the scanning voltage can adjust the repetition rate of the pulse and has a frequency of 1 Hz. There will be two peaks on the envelope of cross-correlation pattern, and both peaks can be used to obtain the distance information. When the laser propagates in vacuum and the system is stabilized, the distance between these two peaks is constant, and we can use this distance to obtain the important factor N, which is used to describe the number of the pulse. As a result, we can realize absolute distance measurement without the help of other measurement systems. However, due to the dispersion of the medium,the distance between these two peaks is not constant, which means t

关 键 词：光学频率梳 绝对测距 谐振腔扫描法光学采样 非对称互相关 

分 类 号：O439[机械工程—光学工程]