Radial distribution of the fictive temperature in pure silica optical fibers by micro-Raman spectroscopy

Micro-Raman spectra are performed at different radial positions in order to determine the fictive temperature distribution in pure silica optical fibers. As-received and annealed optical fibers are compared and Raman results reveal a large decrease in the fictive temperature after annealing. The fictive temperature gradient between the core and the edge of the optical fiber can be eliminated after annealing and the spectroscopic decoupling between stress and the fictive temperature variation is discussed. The micro-Raman is a good probe in determining the spatial distribution of the fictive temperature in the micrometer length scale. (c) 2008 American Institute of Physics.