Method for preparing a fused silica glass body co-doped with a rare earth element and aluminum

A method for the preparation of a fused silica glass body co-doped with a rare earth element and aluminum which comprises the successive steps of:

• (a) introducing a silicon compound in the form of vapor and an aluminum compound in the form of vapor into an oxyhydrogen flame to effect co-pyrolysis of the silicon and aluminum compounds into their respective oxides in the form of particles which are deposited on a substrate in the form of a porous silicon oxide body containing aluminum oxide;
• (b) soaking the porous body of silicon oxide containing aluminum oxide with a solution of a compound of a rare earth element in a solvent to impregnate the porous body;
• (c) drying the porous body of silicon oxide impregnated with the solution;
• and
• (d) heating the dried porous body of silicon oxide containing aluminum oxide and the rare earth compound at an elevated temperature to effect sintering and vitrification thereof into a transparent fused silica glass body co-doped with the rare earth element and aluminum.