Wide Temperature-Range Brillouin and Rayleigh Optical-Time-Domain Reflectometry in a Dispersion-Shifted Fiber

The temperature dependences of spontaneous Brillouin and Rayleigh scattering intensities in a dispersionshifted fiber have been measured over a wide temperature range by optical-time-domain reflectometry. It was found that spontaneous Brillouin and Rayleigh intensities normalized by room-temperature values have linear dependences on temperature, with coefficients (0.26 +- 0.02)% (degree)C and (0.015 +- 0.002)% (degree)C in temperature ranges -27 -819 and 29 -827 (degree)C, respectively. Experimental results have demonstrated that both kinds of scattering can be used for distributed high-temperature measurement.