In standard single-end-access Brillouin optical correlation-domain reflectometry (BOCDR), the systematic error caused by the phase difference between amplitude modulation (AM) and frequency modulation (FM) in the light source can be up to tens of megahertz, causing considerable errors in strain and temperature measurement. In this letter, we develop a new concept of two-end-access BOCDR, in which light is injected into each end of a sensing fiber in turn and the measured results of the Brillouin frequency shift distributions are combined. We numerically show that this configuration can suppress the systematic error caused by the AM-FM phase difference by approximately 90%.

在标准的单端接入布里渊光相关域反射计 (BOCDR) 中，光源中调幅 (AM) 和调频 (FM) 之间的相位差引起的系统误差可达数十兆赫兹，导致在应变和温度测量中存在相当大的误差。在这封信中，我们提出了两端接入 BOCDR 的新概念，其中光依次注入传感光纤的每一端，并结合布里渊频移分布的测量结果。我们从数值上表明，这种配置可以将 AM-FM 相位差引起的系统误差抑制约 90%。