基于法布里-珀罗低相干干涉的绝对距离测量系统  

Quick absolute distance measurement system based on low-coherence Fabry-Perot interferometry

作　　者：王韵致 谢芳[1] 王辉[1] 韩飞 WANG Yun-zhi;XIE Fang;WANG Hui;HAN Fei(Optical Science and Technology Laboratory,Department of Physics,School of Science,Beijing Jiaotong University,Beijing, 100044)

机构地区：[1]北京交通大学理学院光电信息科学与工程实验室

出　　处：《光电子．激光》2019年第7期731-736,共6页Journal of Optoelectronics·Laser

基　　金：北京市自然科学基金(3172024)资助项目

摘　　要：提出了一种基于光纤法布里-珀罗低相干干涉的绝对距离测量系统,不仅能对绝对距离进行测量,而且还能对温度、压力、应力等量进行绝对测量。系统利用闪耀光栅将来自法布里-珀罗干涉仪的低相干干涉信号进行散射,使不同波长的干涉信号由线阵CCD不同的像元探测。利用CCD探测到的干涉信号相邻波谷的波数差得到法布里-珀罗干涉仪的腔长,从而实现绝对距离测量。与其它低相干干涉测量系统相比,此系统无需扫描干涉仪的光程,一次成像即实现测量。测量系统简单,测量速度快,对静态物理量和动态物理量都能进行测量。系统的光纤结构使得它还能进行远程测量。实验结果表明系统对绝对距离测量的分辨率可达3.317 nm,10次重复测量的标准差为10.7 nm。A quick absolute distance measurement system,which also has great potential application to temperature,pressure,and strain measurements,is proposed in this paper.Compared to most available low-coherence interferometric systems that have been used to conduct absolute measurements,this system does not require scanning of the optical path difference during the measurement,and is designed with easily available and inexpensive optical elements to provide a feasible multipurpose method applicable to industries.The optical fiber configuration endows itself with remote sensing ability.Based on dispersing the low-coherence interferometric signal from an optical fiber Fabry-Perot(F-P) interferometer,the system needs only one frame captured by a linear array charge-coupled device(CCD) rather than scanning the OPD to measure the absolute cavity length of the F-P interferometer.Therefore,it can perform absolute and quick measurements while being free from environmental disturbances.Parameters that have a linear relationship with cavity length,such as displacement,temperature,pressure,and strain,can also be measured by this system under conditions that improve the F-P interferometer structure.The sensing head can be very small so as to be embedded in remote and harsh environments.Experimental results for absolute distance show that the measurement resolution can be as high as 3.317 nm and the standard deviation of 10 repeated measurements is 10.7 nm.

关 键 词：低相干干涉 法布里-珀罗干涉仪 绝对距离测量 远程测量 

分 类 号：TN2[电子电信—物理电子学]