BigPatents India

A single mode optical waveguide fiber having a relatively large effective area, a negative total dispersion at 1560 nm and a low dispersion slope has a segmented core having a central segment (10), a first annular segment (12), a second annular segment (14) and a third annular segment (16). Each segment has a relative refractive index percent, and an inner and outer radius. The relative refractive index percent and the radii of each core segment are chosen from the following ranges: the relative index of the central segment within the range of about 0.4 % to about 0.9 %; the relative index of the first annular segment within the range of about -0.2 % to about 0.1%; the relative index of the second annular segment within the range of about 0.2 % to about 0.5 %; the relative index of the third annular segment within the range of about -0.2 % to about 0 %; the outer radius (40) of the central segment within the range of about 2.3 m and about 4 m; the center radius (44) of the third annular segment within the range of about 7.8 m and about 10 m; and the width of the third annular segment within the range of about 0.5 m to about 3.5 m.