Slope-assisted Raman distributed optical fiber sensing
Jian Li, Xinxin Zhou, Xu Yang, Lijun Qiao, Jianzhong Zhang, Mingjiang Zhang
Abstract
Raman distributed optical fiber sensing is required to achieve accurate temperature measurements in a micro-scale area. In this study, we first analyze and demonstrate the pulse transmission feature in the temperature variation area and the superposition characteristics of Raman optical time-domain reflectometry (OTDR) signals by numerical simulation. The equations of superimposed Raman anti-Stokes scattered signals at different stages are presented, providing a theoretical basis for the positioning and physical quantity demodulation of whole optical fiber systems based on the OTDR principle. Moreover, we propose and experimentally demonstrate a slope-assisted sensing principle and scheme in a Raman distributed optical fiber system. To the best our knowledge, this is the first experimental demonstration of Raman distributed optical fiber sensing in a centimeter-level spatial measurement region.