Method of fabricating rare earth doped optical fibre

Abstract

The present invention provides a method of fabricating rare earth doped preforms and optical fibers by a combination of modified chemical vapor deposition (MCVD) process and solution doping technique said MCVD process is used to develop matched or depressed clad structure inside a silica glass substrate tube followed by deposition of porous silica soot layer containing GeO, POor such refractive index modifiers by the backward deposition method for formation of the core and presintering the deposited particulate layer by backward pass with flow of GeCland/or corresponding dopant halides, soaking the porous soot layer into an alcoholic/aqueous solution of RE-salts containing codopants such as AlClin definite proportion, drying, oxidation, dehydration and sintering of the RE containing porous deposit and by collapsing at a high temperature to produce the preform followed by drawing the fibers by known technique to produce fibers with suitable core-clad dimensions and geometry.