Fictive temperature of silica glass optical fibers - re-examination

Fictive temperatures of several commercial silica glass optical fibers were re-measured using IR reflection method, both on the fiber surface and on t he fiber cross-section. In order to increase the cross-sectional area of th e fiber for a larger IR beam, fibers were sliced approximate to5 degrees of f the fiber axis direction. The IR reflection peak wavenumber was nearly un iform across the fiber cladding and was close to the value obtained earlier for the fiber surface. The IR wavenumbers were converted to fictive temper ature using the extrapolated relation between the IR peak wavenumber and th e fictive temperature. In order to ascertain the validity of the extrapolat ion, the fictive temperature was also obtained by extrapolating the known r elation between the cooling rate and the fictive temperature of the fibers. The fictive temperature of the optical fibers was estimated to be in the r ange 1600-1700 degreesC and its radial distribution in the cladding was nea rly uniform. contrary to earlier results. (C) 2001 Elsevier Science B.V. Al l rights reserved.