LARGE EFFECTIVE AREA FIBER WITH GRADED INDEX GE-FREE CORE

摘要

According to some embodiments an optical waveguide fiber comprises (i) a Ge free core having an effective area of 100 μm2to 150 μm2, at 1550 nm wavelength, said core comprising: a) a central core region extending radially outwardly from a centerline to a radius r1, and having a relative refractive index percent profile &Dgr;1(r) in % measured relative to pure silica, wherein −0.1%≦̸&Dgr;1(r)≦̸0.12%, wherein the central core region has a maximum relative refractive index percent, &Dgr;1MAX; (b) a first annular core region surrounding and directly adjacent to the central core region, having an α value 1.5≦̸α≦̸10, and extending to an outer radius r2, wherein 6 μm≦̸r2≦̸10 μm, and having a relative refractive index percent profile, &Dgr;2(r) in % measured relative to pure silica, a minimum relative refractive index &Dgr;2MIN, a maximum relative refractive index &Dgr;2MAX and the relative refractive index measured at a radius r=2 μm, wherein 0.45≦̸&Dgr;2≦̸0; −0.25≧&Dgr;2MIN≧−0.45 and &Dgr;1MAX≧&Dgr;2(r=2 μm); (c) a fluorine doped second annular region surrounding and directly adjacent to the first annular core region and extending to a radius 20 μm≦̸r3≦̸30 μm and having a negative relative refractive index percent profile, &Dgr;3(r) in %, measured relative to pure silica, with a minimum relative refractive index percent &Dgr;3MIN and −0.5%<&Dgr;3MIN<−0.25%; and &Dgr;3MIN≦̸&Dgr;2MIN; (ii) a cladding surrounding the core and having a relative refractive index percent &Dgr;4(r) in % measured relative to pure silica and a minimum refractive index delta &Dgr;4MIN, and −0.4%<&Dgr;4<−0.2%; wherein the relative refractive index profile of the optical fiber is selected to provide attenuation of no more than 0.17 dB/km at the 1550 nm wavelength.