FPM DOFS中stokes或anti-stokes的频移分析

Analysis of Stokes or Anti-stokes Light's Frequency Shift in FPM DOFS

近年来分布式光纤传感器（DOFS）发展很快，利用四波混频脉冲移位的分布式光纤传感器（FPMDOFS）是最近提出的一种新型分布式光纤传感技术，本文对FPMDOFS中stokes／anti－stokes频移进行了理论分析，给出频移计算公式，并指出在激励光脉冲功率衰减较大的情况下，应考虑由自相位调制引起的stokes／anti－stokes中心频率偏移。

DOFS(Distributed Optical-Fiber Sensor) is an active field of research in recent Distributed Optical-Fiber Sensing by four-photon mixing pulse walk-off is a noval technique that was recently presented. In the paper, we analyze the stokes or anti-stokes light's .frequency shift in FPM DOFS, and give the calculating formula. We also point out that the frequency shin due to SPM (Self-Phase Modulation )should be considered, if the peak power of pump light is attenuated too much.