Distributed optical fiber temperature sensor based on spontaneous Brillouin scattering

In order to achieve remote on-line measurement and monitoring for temperature, a new method which is technique of the distributed optical fiber sensor being basic on spontaneous Brillouin scattering,. is proposed to use. This paper describes the principle of distributed optical fiber sensing technique based on spontaneous Brillouin scattering light (SBSL). It discusses the technology in the following aspects: basic working theory, structure, system characteristics and signal handling technology. Brillouin scattering light with temperature signal is obtained without the influence of Rayleigh scattering which is rejected extremely by the double-pass all-fiber Mach-Zehnder interferometer. Then, measuring frequency shift and intensity of the spontaneous Brillouin scattering light, it ensures the spatial resolution and the temperature resolution. Experimental results indicate that the use of the spontaneous Brillouin scattering technology enables spatial resolution and temperature resolution accuracy to reach 35cm and 4degreesC.