A frequency-modulated continuous-wave technique is used to detect the presence of frequency shifts in the Rayleigh-backscattered light in a single-mode optical fiber as a result of a changing temperature. The system is able to detect a rate of temperature change of 0.014 K/s, when a 20-cm length of fiber is heated. The system is also able to demonstrate a spatial resolution of better than 15 cm.
© 1994 Optical Society of America
R. Rathod, R. D. Pechstedt, D. A. Jackson, and D. J. Webb, "Distributed temperature-change sensor based on Rayleigh backscattering in an optical fiber," Opt. Lett. 19, 593-595 (1994)