LARGE EFFECTIVE AREA FIBER WITH GE-FREE CORE

摘要

An optical waveguide fiber comprising: (i) a Ge free core having an effective area of 90 µm2 to 160 µm2, at a 1550 nm wavelength, and a value 12 = a =25, said core comprising: (a) a central core region extending radially outwardly from a centerline to a radius 0 µm =r0 = 2 µm, and having a relative refractive index percent profile ?0(r) in % measured relative to pure silica, wherein -0.1 % = ?0(r) =0.1 %, wherein the central core region has a maximum relative refractive index percent, ?0MAX; (b) a first annular core region surrounding and directly adjacent to the central core region and extending to an outer radius r1, wherein 4.8 µm =r1 =10 µm, and having a relative refractive index percent profile, ?1 (r) in % measured relative to pure silica, and a minimum relative refractive index, ?2MIN, and the relative refractive index measured at a radius r = 2.5 µm being: -0.15 1 (r =2.5 µm)=0, and ?0MAX =?1(r =2.5 µm); (c) a fluorine doped second annular region surrounding and directly adjacent to the first annular core region and extending to a radius 13 µm =r2 = 30 µm and having a negative relative refractive index percent profile, ?2(r) in %, measured relative to pure silica, with a minimum relative refractive index percent ?2MIN being: ?2MIN 1(r=2.5 µm), and -0.7 % = ?2M?N = -0.28 %; (ii) a cladding surrounding the core and having a relative refractive index percent ?c (r) in % measured relative to pure silica, and ?c (r) = ?2MIN ? 0.3 %; wherein the relative refractive index profile of the optical fiber is selected to provide attenuation of no more than 0.175 dB/km at the wavelength of 1550 nm.