An
optical fiber according to an embodiment of the present invention comprises: a glass core extending from a centerline to a
radius R1 wherein R1 is greater than about 5 μm; a glass cladding surrounding and in contact with the core, the cladding comprising: (i) a first annular region extending from the
radius R1 to a
radius R2, the first annular region comprising a radial width, W2=R2−R1, (ii) a second annular region extending from the radius R2 to a radius R3, and comprising a radial width, W3=R3−R2, and (iii) a third annular region surrounding the second annular region and extending from the radius R3 to an outermost glass radius R4; wherein the core comprises a maximum
relative refractive index, Δ1MAX, relative to the third annular region, and wherein Δ1MAX is greater than about 0.1% and less than about 0.3%; the first annular region has a
refractive index delta Δ2(r) is less than about 0.025%; wherein the second annular region comprises a minimum
relative refractive index, Δ3MIN, relative to the third annular region;wherein Δ1MAX>Δ2MAX>Δ3MIN, and Δ2MIN>Δ3MIN<0; andwherein the core and the cladding provide a
fiber with cable cutoff less than 1500 nm, and an effective area at 1550 nm greater than 95 μm2 and
bend loss of ≦0.5 dB / turn on a 20 mm
diameter mandrel.