Patent ID: 7676129

Claim:
An optical fiber comprising: a core comprising: a central core region extending from a centerline to a radius R C ; and an annular core region surrounding and in contact with the central core region extending from R C to a radius R 3 ; and a cladding surrounding and in contact with the core comprising: an annular ring region extending from R 3 to a radius R 4 , the annular ring region comprising a radial width, W=R 4 −R 3 ; and an annular outer region extending from R 4 to an outermost glass radius R 5 ; wherein the central core region comprises a maximum relative refractive index, percent, Δ 1MAX ; the annular ring region comprises a minimum relative refractive index percent, Δ 3MIN ; wherein 0.30%≦Δ 1MAX <0.45%, Δ 3MIN ≦−0.2%, W≧2 μm, and R C /R 3 ≧0.5; and wherein the core and the cladding provide a cabled cutoff wavelength of less than 1260 nm, a zero dispersion wavelength between 1300 and 1324 nm, a mode field diameter at 1310 nm of between 8.20 and 9.50 μm, a dispersion slope at the zero dispersion wavelength of less than 0.092 ps/nm 2 -km, and a 10 mm diameter bend loss of less than 1.0 dB/turn.