保偏光纤拍长与折射率测量技术研究

Study on Measurement Technique of Beat Length and Refractive Index of Polarization Maintaining Fiber

拍长和折射率是表征保偏光纤产品性能的重要指标,随着保偏光纤在光纤通信和光纤传感等领域的广泛应用,对拍长和折射率参数的准确测量十分重要。基于白光干涉技术研制了保偏光纤拍长测量装置,通过测量保偏光纤上两个应力点之间的几何长度和对应耦合点之间的光学长度,实现了拍长的高精度测量,重复性优于4μm。基于数字全息显微层析成像技术,研制了保偏光纤折射率测量装置,通过记录不同旋转角度下的数字全息图,经滤波反投影处理后重建保偏光纤的二维横截面的折射率分布,实现了折射率的高精度测量,重复性优于10^(-4)。

Beat length and refractive index are two import ant parameters to characterize the performance of polariza-tion maintaining fiber,with the widely application of polarization maintaining fiber in the field of fiber communica-tion and sensing,it is very important for the high accuracy measurement of beat length and refractive index.Based on the white light interferometry,a beat length measuring device of polarizat ion mai ntaining fiber is developed,by measuring the geometric length between the two stress points on the polarization maintaining fiber and the optical length between the corresponding coupling poi nts,high precision measurement of beat length is realized,and the measurement repeatability is better than 4μm.Based on the digital holographic microscopy tomography,a refractive in-dex measuring device of polarizat ion maintaining fiber is developed,by recording the digital hologram at different angles,the refractive index profile of two-dimensional cross section of the polarization maintaining fiber is reconstructed,then high precision measurement of refractive index is realized,and the measurement repeatability is better than 10^(-4).