초록 ▼

Rare earth elements, e.g. Nd, are introduced into optical glass fibre for telecommunications by evaporating a suitable salt, e.g. NdCl3, from a glass sponge into the gas stream used to deposit core material. Preferred sponges are in the form of tubes having an outer impervious layer and an inner por

Rare earth elements, e.g. Nd, are introduced into optical glass fibre for telecommunications by evaporating a suitable salt, e.g. NdCl3, from a glass sponge into the gas stream used to deposit core material. Preferred sponges are in the form of tubes having an outer impervious layer and an inner porous layer. These sponges are conveniently made by MCVD and the impregnation is preferably carried out using an alcoholic solution of the impregnant.

대표청구항 ▼

A method of making a source for providing metal compounds into MCVD, which method comprises: (i) depositing a porous silica layer on the inner surface of a substrate tube by MCVD, said MCVD beihg performed at a temperature below the sintering temperature of the deposited silica, (ii) soaking the pro

A method of making a source for providing metal compounds into MCVD, which method comprises: (i) depositing a porous silica layer on the inner surface of a substrate tube by MCVD, said MCVD beihg performed at a temperature below the sintering temperature of the deposited silica, (ii) soaking the product of the MCVD in a solution of a metal compound; and (iii) evaporating the solvent of the solution whereby the porous layer is impregnated with the metal compound.