Patent ID: 7526169

Claim:
An optical fiber comprising a first region comprising Δ 1 MAX , a second region surrounding the first region and comprising Δ 2 MAX and a width W 2 , and a third region surrounding the second region and comprising Δ 3 MIN , wherein Δ 1 MAX >Δ 2 MAX >Δ 3 MIN , wherein a mode field diameter at 1550 nm is greater than 9.0 μm, wherein W 2 is at least 1 micron wide, and wherein the optical fiber comprises a length L 2 and a measured fiber cutoff wavelength corresponding to the length L 2 , λ C2-L2 , greater than 1500 nm, and the optical fiber has a core cutoff wavelength, λ C2-TH , less than 1300 nm.