Patent ID: 6920271

Claim:
An optical waveguide fiber having reduced polarization mode dispersion comprising: a core region bounded by a clad layer, said optical waveguide fiber having a birefringence having a fast axis that varies in direction from point to point along at least a portion of the length of said optical waveguide fiber, the variation in direction of the fast axis being in accord with a pre-selected pattern formed in the optical waveguide fiber by a spin function, α(z), wherein the spin function α(z), the spin magnitude, and the modulation parameters are selected to provide, for a fiber having a beat length greater than or equal to about 0.5 meters, a polarization mode dispersion reduction factor which remains less than or equal to 0.50 when the spin magnitude varies up to about 35% of a target spin magnitude value, and where the spin function α(z) is of the form: α(z)=α 0 [ƒ 1 (γ 0 z+γ 1 ƒ 2 (γ 2 z))×{ƒ 3 (γ 3 ,γ 4 z)}], where z is distance along the long axis of the optical waveguide fiber, α 0 is spin magnitude, f 1 , f 2 , and f 3 are periodic functions, and γ 0 , γ 1 , γ 2 , γ 3 , γ 4 are modulation parameters.