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 dispersion-shifted 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)%/degrees C and (0.015 +/- 0.002)%/degrees C in temperature ranges -27-819 and 29-827 degrees C, respectively. Experimental results have demonstrated that both kinds of scattering can be used for distributed high-temperature measurement.