One centimeter spatial resolution temperature measurements in a nuclear reactor using Rayleigh scatter in optical fiber

We present the use of swept wavelength interferometry for distributed fiber-optic temperature measurements in a nuclear reactor. The sensors consisted of 2-m segments of commercially available, single mode optical fibers. The interrogation technique is based on measuring the spectral shift of the intrinsic Rayleigh backscatter signal along the optical fiber and converting the spectral shift to temperature.