| 摘要 |
<p>According to some embodiments an optical waveguide fiber comprises: (i) a Ge free core having an effective area of 90μm2 to 160μm2, at a 1550 nm wavelength, andαvalue 12≰α≰25, said core comprising: (a) a central core region extending radially outwardly from a centerline to a radius 0μm≰r0≰2μm, and having a relative refractive index percent profileΔ0(r) in % measured relative to pure silica, wherein−0.1%≰Δ0(r)≰0.1%, wherein the central core region has a maximum relative refractive index percent,Δ0MAX; (b) a first annular core region surrounding and directly adjacent to the central core region and extending to an outer radius r1, wherein 4.8μm≰r1≰10μm, and having a relative refractive index percent profile,Δ1(r) in % measured relative to pure silica, and a minimum relative refractive index,Δ2MIN, and the relative refractive index measured at a radius r=2.5μm being:−0.15≰Δ1(r=2.5μm)≰0, andΔ0MAX≧Δ1(r=2.5μm); (c) a fluorine doped second annular region surrounding and directly adjacent to the first annular core region and extending to a radius 13μm≰r2≰30μm and having a negative relative refractive index percent profile,Δ2(r) in %, measured relative to pure silica, with a minimum relative refractive index percentΔ2MIN being:Δ2MIN≰Δ1(r=2.5μm), and−0.7%≰Δ2MIN≰−0.28%; (ii) a cladding surrounding the core and having a relative refractive index percentΔc(r) in % measured relative to pure silica, andΔc(r)=Δ2MIN±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.</p> |
