2×2 juxtaposed Type Optical Fiber Raman Temperature Sensor

Abstract

We report on a 2times2 juxtaposed type optical fiber Raman temperature sensor. Two output ports of the 2times2 couple make coupling of the optical fiber respectively and two optical fiber made fascis will be a item of the sensor optical fiber. On the condition that the quasi-continuous wave inputs, the couple has the nonlinear switch theory; hence the signals received by the detector will take four times of what a single sensor optical fiber does. A new demodulated method for the simultaneous distributed temperature measurement in an optical fiber based on spatially resolving the anti-Stokes signals of the spontaneous Raman back-scattering, the sensitivity of sensor is heightened. We make up the experimental system and achieve 5 km of length, 1 m of distance resolution, accuracy to plusmn0.1degC