Estimating the effect of Ge doping on the acoustic damping coefficient via a highly Ge-doped MCVD silica fiber

We estimate the effect of Ge doping on the acoustic damping coefficient of silica fibers. We show that an acoustically multimode fiber with a characteristic central index dip, such as that observed in modified chemical-vapor deposition (MCVD)-type fibers, can provide adequate data for a reasonable estimation. This may result from the fact that the scattering integral of each acoustic mode in such a waveguide is strongly position-dependent in the radial direction where there is a varying Ge content. (C) 2009 Optical Society of America