Rayleigh scattering of silica glass and silica fibers with heat treatment

We investigated the effect of heat treatment on the Rayleigh scattering of silica glass and silica fibers in relation to the fictive temperature (T(f)). The scattering intensity of silica glass changes in proportion to T(f) which varies according to the condition of the heat treatment. As-drawn silica fibers exhibit T(f) values close to 1600 degrees C. The scattering intensity of a fiber after heat treatment becomes 25% less than that before treatment. On the assumption that a linear relation between Rayleigh scattering and T(f) is valid for glasses and fibers, this result suggests that a further loss reduction can be expected in silica fibers by reducing T(f).