Rare-earth doped optical fibers for temperature sensing

The feasibility of using a variety of rare-earth doped optical fibers for measuring spatially averaged temperatures from approximately 0 to approximately 100 degrees C over distances of 10 to 20 m is discussed. Such distributed temperature sensors would be particularly well-suited for building climate control systems and industrial processing applications. The temperature-dependent absorption spectra of 6 MCVD processed fibers containing different concentrations of Nd/sup 3+/, Pr/sup 3+/, and Yb/sup 3+/ rare-earth ions were characterized and used to determine thermally active dopant species, optimal dopant concentrations, and most sensitive operating wavelengths for use as dual wavelength distributed temperature sensors.<
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