Single optical channel based Raman distributed optical fiber temperature measurement system
To address the issue of position correction and temperature distortion caused by walk-off effects in conventional Raman distributed optical fiber temperature measurement systems,a new single optical channel scheme is proposed.This scheme incorporates a model for scattered light power correction and a temperature calibration algorithm to ensure accurate temperature measurement along the fiber.First,tem-perature demodulation formulas for single Raman Stokes and anti-Stokes light are derived based on the temperature sensitivity principle of Raman scattering.Since temperature demodulation via a single optical channel is hindered by the stability of pulse lasers and photodetectors,a temperature calibration unit and signal power correction algorithm are developed.An experimental platform was then built to compare the temperature measurement performance of traditional dual-channel systems with single channel Raman Stokes and Raman anti-Stokes schemes.Experiments on a 12 km fiber demonstrated that the scheme using Raman anti-Stokes light achieves a temperature deviation of-0.3℃to 2.2℃,with a root mean square er-ror of 1.0℃and a spatial resolution of 6 m,showing superior performance over traditional systems.This single channel system with signal power correction offers high sensitivity and eliminates the walk-off cor-rection issue inherent in dual-channel systems,proving its practical value.
optical fiber sensorRaman scatteringtemperature measurementoptical time domain re-flectingdistributed
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