Effect of stress on the structural relaxation behavior of glasses

A modified structural relaxation function has been introduced here that takes into account the effect of stress on the structural relaxation behavior of glasses. This modified structural relaxation function is used to predict the evolution of fictive temperature in core and clad glasses of fluorine doped optical fibers, when these are annealed at different temperatures. The methods are applied to the conditions reported in Saito et al. [K. Saito, M. Yamaguchi, A.J. Ikushima, K. Ohsono, Y. Kurosawa, J. Appl. Phys. 95 (4) (2004) 1733], 2004), and good agreement between the predictions and experimental observations (of Saito et al.) is obtained for all four core and clad glasses (with varying fluorine levels) annealed over a broad temperature range. A critical discussion of the methods and the results is also presented.