Patent ID: 6128928
Filing Date: 2000-10-10
Classification: C03B,C03C,G02B

Abstract:
In a process for fabricating a core preform having utility in making single-mode optical waveguide fibers, comprising reacting a core soot precursor composition and depositing central core region glass soot on a substrate, and then reacting an inner cladding soot precursor composition and depositing inner cladding region glass soot over said central core region glass soot to yield said core preform, the improvement comprising including in said inner cladding soot precursor composition, a precursor to germanium dioxide at a concentration within the range of about 0.03 to about 0.3 mole percent, effective to yield inner cladding region glass soot comprising between about 0.1 percent by weight to 0.4 percent by weight of germanium dioxide beyond a 0.1 normalized radial distance from an outer edge of a core of the optical fiber.