Ytterbium-doped aluminum-codoped sol-gel silica glass fiber

In this paper, a ytterbium-doped aluminum-codoped silica sol-gel fiber Yb:Al:SiO/sub 2/ produced by sol-gel method is presented. The fiber was investigated with respect to its optical properties such as index of refraction, attenuation, numerical aperture and fluorescence properties. With the help of FTIR, the residual amount of hydroxyl-groups and its influence on the luminescence yield by nonradiative multi-phonon relaxations were determined. XRD measurements were performed to assess the amorphous structure of the sol-gel core materials.