Patent ID: 6317552
Filing Date: 2001-11-13
Classification: G02B

Abstract:
A dispersion compensating single mode optical waveguide fiber comprising:a central core glass region, surrounded by and in contact with a clad glass layer, at least a portion of the core glass region having a refractive index higher than the maximum refractive index of the clad layer, the central core glass region having a center, a refractive index profile, and a radius, and the clad glass layer having a refractive index profile,in which, the refractive index profile of the central core region includes at least five segments,a center segment having a cross sectional area distributed substantially symmetrically about the core center and having a relative index .DELTA..sub.c %, which is in the range of 1.5% to 3.5%, and a radius,a number j of annular segments surrounding the center segment beginning with a first annular segment abutting the center segment, a second annular segment abutting the first annular segment and a jth annular segment abutting the (j-1)th segment to form a core having a center segment and j annular segments, the respective annular segments having a relative index .DELTA..sub.j % and a width, w.sub.j, measured along the .DELTA.%=0 line, where j is an integer .gtoreq.4;in which .DELTA..sub.c %>.DELTA..sub.j %.gtoreq.0 for all values of j, and .DELTA..sub.j for j an even number is greater than .DELTA..sub.j for j an odd number;in which the respective relative indexes, the center segment radius and annular segment widths are selected to provide a dispersion more negative than about -85 ps/nm-km at a pre-selected wavelength.