Optical waveguide fiber with titania-silica outer cladding and method of manufacturing

A method for manufacturing a fatigue resistant optical waveguide fiber with a TiO.sub.2 -SiO.sub.2 outer cladding, comprising,

• forming a doped SiO.sub.2 preform with a core portion and a cladding portion,
• depositing a layer of TiO.sub.2 -SiO.sub.2 soot with a TiO.sub.2 concentration profile on the outside of said cladding portion to create an augmented preform, said TiO.sub.2 -SiO.sub.2 soot layer including at least one cylindrical axially symmetric layer with thickness of about 0.1 .mu.m or greater having a TiO.sub.2 concentration greater than 10.5 wt. %,
• exposing said augmented preform to an atmosphere containing chlorine and oxygen at a temperature within the range of about 900.degree. to 1400.degree. C., said oxygen being present in a concentration sufficient to substantially reduce the depletion of TiO.sub.2 from said augmented preform that results from the presence of chlorine in said exposing step and/or to substantially reduce the migration of TiO.sub.2 toward the center of said augmented preform thereby substantially maintaining said TiO.sub.2 concentration profile of said TiO.sub.2 -SiO.sub.2 layer,
• consolidating said preform into a glass blank with a TiO.sub.2 -SiO.sub.2 outer cladding layer, and
• drawing said glass blank with a TiO.sub.2 -SiO.sub.2 outer cladding layer into an optical waveguide fiber with inhomogeneities in the outer TiO.sub.2 -SiO.sub.2 layer of the fiber.