Optical properties of sol-gel derived Sb-doped silica glass

The sol-gel preparation of Sb-doped silica glass with high refractive index was investigated. A base-catalyzed low density gel rod with dopant content up to 15 mol% was prepared. Sintering resulted in an OH-free Sb-doped silica glass rod with a maximum specific refractive index of 3.17% with reference to pure silica. Above 5 mol% the refractive index was radially graded with a maximum at the center. Optical fiber fabricated from the 5 mol% Sb-doped silica as a core exhibited optical loss of about 700 dB/km at 0.6 mu m. The loss may be attributed to coloration due to multivalent Sb. (C) 1997 Published by Elsevier Science B.V.