光频域反射计的测量不确定度分析

Analysis of OFDR Measurement Uncertainty

光纤长度测量在光通信和光传感等领域有重要应用。光频域反射计(OFDR)测量光纤长度具有较高的分辨率和精度,可以达到10-6量级,目前尚无光纤长度标准对其进行有效的计量。先从理论上分析了OFDR对光纤长度的测量不确定度,再采用可调光纤延迟线对OFDR测量不确定度评估结果进行实验验证。以LUNA公司OBR4600OFDR为例评价出在100m量程下,其测量不确定度约为100μm。

Fiber length measurement has important applications in the field of optical communication and optical sensing. The optical frequency domain reflectometer （OFDR） is such a tool with high-resolution and high-accuracy that can reach l0-6 magnitude. There is no optical fiber length standard to measure it effectively at present. First, the uncertainty comes from the measurement of optical fiber length by OFDR is analyzed theoretically. Then, use the adjustable optical fiber delay line to experimentally verify the evaluation results of the OFDR measurement uncertainty. Taking OBR4600 OFDR from LUNA as an example, the measurement uncertainty is evaluated about 100 μm at the measuring range of 100 m.