Patent ID: 7003203

Claim:
A dispersion compensating fiber, comprising: a refractive index profile having a central core segment with an inner peak having a relative refractive index Δ i % located at a radius r i of between 0.0 μm and 1.0 μm, an outer peak with a relative refractive index Δ 1 % located at a radius r o between 1.5 μm and 2.5 μm, and a trough positioned between the inner peak and outer peak having a minimum relative refractive index Δ t % less than both Δ i % and Δ 1 %, wherein the minimum relative refractive index Δ t % is between 0.3% to 1.0%, a moat segment, surrounding the central core segment, having a relative refractive index Δ 2 %, and a ring segment, surrounding the moat segment, having a positive relative refractive index Δ 3 % wherein Δ t % and Δ 3 % are greater than Δ 2 % wherein the dispersion compensating fiber exhibits negative dispersion at 1550 nm.