RARE EARTH ELEMENT DOPED GLASS

摘要

PROBLEM TO BE SOLVED: To prevent the deposition of a high m.p. material at the time of sintering a porous glass produced by an outside process such as a VAD soln. impregnation method. SOLUTION: When a rare earth element is added to a host glass having an SiO2 -base compsn. to obtain the objective rare earth element doped glass, the host glass is doped with Al and F. A material that increases the refractive index of the host glass or a material that reduces the softening temp. of the host glass is further added to the compsn. of the host glass if necessary.