Dispersion managed fibers having reduced sensitivity to manufacturing variabilities

An optical waveguide fiber for use in a dispersion managed optical communication system comprising a core of transparent material surrounded by a cladding of transparent material having a refractive index ncl, said core comprising three radially adjacent regions which in order of increasing radius are:

• (a) a central core region having:
• (i) a maximum index of refraction nc such that Δc% is greater than zero and less than about 1.2, where Δc%=100·(nc2−ncl2)/2ncl;
• (ii) an alpha profile with an alpha value less than about 2.3;
• and
• (iii) an outer radius Rc;
• (b) a moat region having an outer radius Rm and a minimum index of refraction nm such that:
• Δm%≦−0.55 for Rc/Rm<0.6;
• Δm%≦−0.50 for Rc/Rm<0.45;
• Δm%≦−0.45 for Rc/Rm<0.4;
• or
• Δm%≦−0.30 for Rc/Rm<0.3;
• where Δm%=100·(nm2−ncl2)/2ncl, said moat region comprising, in order of increasing radius, first, second, third, and fourth radially adjacent regions wherein:
• (i) the index of refraction decreases throughout the first region;
• (ii) the index of refraction increases substantially linearly in the second region;
• (iii) the index of refraction increases substantially linearly in the fourth region;
• and
• (iv) the third region is a transition region which smoothly connects the third and fourth substantially linear regions;
• and
• (c) a ring region having a maximum refractive index nr such that Δr% is greater than zero and less than +0.5, where Δr=100·(nr2−ncl2)/2ncl.

A method of reducing the variation in dispersion of an optical waveguide fiber due to manufacturing variabilities comprising:

• (a) selecting a profile for the fiber which comprises a central core region, a moat region, and a ring region, wherein the central core region has an alpha profile with an alpha value of less than about 2.3;
• and
• (b) manufacturing a fiber which substantially has the profile selected in step (a);
• wherein the fiber manufactured in step (b) has:
• (i) a dispersion slope whose magnitude is less than 0.04 ps/nm2-km;
• and
• (ii) a dispersion the magnitude of which varies along the length of
• the fiber, the difference between the maximum and the minimum of said magnitude over said length being less than 0.5 ps/nm-km wherein the moat region comprises, in order of increasing radius, first, second, third, and fourth radially adjacent regions wherein:
• (i) the index of refraction decreases throughout the first region;
• (ii) the index of refraction increases substantially linearly in the second region;
• (iii) the index of refraction increases substantially linearly in the fourth region;
• and
• (iv) the third region is a transition region which smoothly connects the third and fourth substantially linear regions.

A method of reducing the variation in dispersion of an optical waveguide fiber due to manufacturing variabilities comprising:

• (a) selecting a profile for the fiber which comprises a central core region, a moat region, and a ring region, wherein the central core region has an alpha profile with an alpha value of less than about 2.3;
• and
• (b) manufacturing a fiber which substantially has the profile selected in step (a);
• wherein the fiber manufactured in step (b) has:
• (i) a dispersion slope whose magnitude is less than 0.04 ps/nm2-km;
• and
• (ii) a dispersion the magnitude of which varies along the length of the fiber, the difference between the maximum and the minimum of said magnitude over said length being less than 0.5 ps/nm-km, wherein the fiber comprises a cladding having an index of refraction ncl and the moat region has a minimum index of refraction nm such that Δm%≦−0.3, where Δm%=100·(nm2−ncl2)/2ncl.

A method of reducing the variation in dispersion of an optical waveguide fiber due to manufacturing variabilities comprising:

• (a) selecting a profile for the fiber which comprises a central core region, a moat region, and a ring region, wherein the central core region has an alpha profile with an alpha value of less than about 2.3;
• and
• (b) manufacturing a fiber which substantially has the profile selected in step (a);
• wherein the fiber manufactured in step (b) has:
• (i) a dispersion slope whose magnitude is less than 0.04 ps/nm2-km;
• and
• (ii) a dispersion the magnitude of which varies along the length of the fiber, the difference between the maximum and the minimum of said magnitude over said length being less than 0.5 ps/nm-km wherein the fiber comprises a cladding having an index of refraction ncl and the moat region has a minimum index of refraction nm such that Δm% is less than zero, where Δm%=100 ·(nm2−ncl2)/2ncl and wherein the central core region has an outer radius Rc, the moat region has an outer radius Rm, and Δm% and the ratio of Rc to Rm satisfy one of the following relationships:
• Δm%≦−0.55 for Rc/Rm<0.6;
• Δm%≦−0.50 for Rc/Rm<0.45;
• Δm%≦−0.45 for Rc/Rm<0.4;
• or;
• Δm%≦−0.30 for Rc/Rm<0.3.