Patent ID: 8464556

Claim:
A method of making an optical fiber comprising depositing silica glass based soot on a substrate to form at least a portion of an optical fiber preform by traversing a soot deposition burner with respect to said substrate at a burner traverse rate greater than 3 cm/sec, thereby depositing a layer of soot having a thickness less than 20 microns for each of a plurality of burner passes; and consolidating said at least a portion of the soot preform inside a furnace to remove greater than 50 percent of the air trapped in said soot preform, said consolidating taking place in a gaseous atmosphere containing krypton, argon, SO 2 , or mixtures thereof under conditions which are effective to trap a portion of said gaseous atmosphere in said preform during said consolidation step, thereby forming a consolidated preform which when viewed in cross section will exhibit at least 50 voids therein.