Patent ID: 7773848

Claim:
An optical fiber comprising: a glass core extending from a centerline to a radius R 1 ; a glass cladding surrounding and in contact with the core, the cladding comprising: an annular inner region extending from R 1 to a radius R 2 , the inner region comprising a radial width, W 2 =R 2 −R 1 , an annular ring region extending from R 2 to a radius R 3 , the ring region comprising a radial width, W 3 =R 3 −R 2 , and an annular outer region extending from R 3 to an outermost glass radius R 4 ; wherein the core comprises a relative refractive index, Δ 1 , relative to the outer region less than 0.45% and an alpha greater than 5; wherein the annular inner region comprises a radial width, W 2 , a minimum relative refractive index, Δ 2MIN , relative to the outer region, and a maximum relative refractive index, Δ 2MAX , relative to the outer region, wherein Δ 2 is zero or negative; wherein the annular ring region comprises: a minimum relative refractive index, Δ 3MIN , relative to the annular outer region, wherein Δ 3MIN ≦−0.15% and ≧−0.4; wherein Δ 1MAX >Δ 2MAX >Δ 3MIN , and Δ 1MAX >Δ 2MIN >Δ 3MIN ; wherein 0.45 <R 1 /R 2 <1; and wherein the annular ring region comprises a profile volume, V 3 , equal to: 2 ⁢ ∫ R 2 R 3 ⁢ Δ ⁡ ( r ) ⁢ ⁢ ⅆ r ; wherein V 3 isgreater than 40%-μm 2 , the core and the cladding provide a cable cutoff less than 1260 nm, a zero dispersion between 1300 and 1324 nm, a mode field diameter at 1310 nm of between 8.20 and 9.50 μm, and a 10 mm diameter mandrel bend loss of less than 1.0 dB/turn.