新一代光纤传感系统对光纤长度测量精度的要求越来越高, 因此提出了一种基于Sagnac干涉仪的光纤长度测量方法, 介绍了该测量方法的基本原理和实验装置, 并进行了不同长度光纤的测量实验, 研究了光源偏振态和光纤扰动对测量结果的影响。结果表明, 所提方法的测量精度可以达到厘米量级, 测量范围可以达到1～10 km。

The measurement accuracy requirement for fiber length is higher and higher in the new generation fiber sensing system. A fiber length measurement method based on Sagnac interferometer is proposed. The basic principle and the experimental setup of the proposed method are introduced. Experiments of fiber length measurement are conducted. The influences of polarization state of light source and fiber disturbance on measurement results are verified. Results show that the measurement accuracy of the proposed method can reach centimeter scale and the measurement range is from 1 km to 10 km.