Distributed Temperature Sensing Based on Rayleigh Scattering in Irradiated Optical Fiber

A low-cost distributed temperature sensing system based on Rayleigh scattering in irradiated optical fibers was first proposed. The prototype was developed with a conventional optical time domain reflectometer and a Ge/P co-doped irradiated fiber of 100 m. Three thermal tests were conducted in the range of -40 degrees C similar to 60 degrees C. Experimental results indicate that the prototype can achieve a temperature resolution of 0.05 degrees C with a spatial resolution of 16.3 m at an average time of 52 s. Furthermore, the temperature resolution of the sensing system was analyzed theoretically with simulations. The simulation results show that a temperature resolution of 0.007 degrees C with a spatial resolution of 5 m is obtained mainly by adjusting the transmission wavelength and increasing the light source power.