基于后向喇曼散射分布式光纤测温系统温度解调方法研究

 讨论了喇曼和瑞利散射光的温度效应。通过具体的理论分析,指出反斯托克斯散射光比斯托克斯散射光的温度灵敏度高,是此类系统解调温度信息的首选对象。详细讨论了 2种解调方法。通过分析对比它们在系统温度灵敏度、相对温度灵敏度与波长关系上的差异,得到了一系列有意义的结论。针对实际测量过程中光纤损耗因素,利用最小二乘法给出了一种“校正”算法。系统实践证明,上述结论是正确、合理的,校正算法是简洁、有效的。

STUDY ON TEMPERATURE DEMODULATION METHODS IN THE DISTRIBUTED OPTICAL FIBER TEMPERATURE SENSOR SYSTEM BASED ON RAMAN BACK-SCATTERING

The temperature effects of Raman and Rayleigh light in the distributed optical fiber temperature sensor system are mainly discussed. The analysis shows that the anti Stokes light temperature sensitivity is much higher than Stokes light and it is why all such sensor systems generally use it for temperature information. Then, two demodulation methods are theoretically analyzed in detail by comparing their system temperature sensitivities. Finally, an algorithm is proposed according to the loss of the sensing optical fiber, which is necessary to an actual sensor system. Application practice has indicated that all the above conclusions are correct and reasonable.