Optical fiber having negative dispersion and low slope in the Erbium amplifier region

摘要

A optical fiber is disclosed that is suitable for use in a dispersion-compensated, optical communication system that is served by Erbium-doped fiber amplifiers. The fiber has a negative chromatic dispersion that is more negative than −0.8 ps/(nm-km) over the wavelength region 1530-1565 nm. and has a dispersion slope that is less than 0.05 ps/(nm²-km). This fiber exhibits an average optical transmission loss that is less than 0.21 dB/km; and its effective area exceeds 50 &mgr;m², which renders it relatively insensitive to bending loss. The optical fiber includes a core of germanium-doped silica whose refractive index is n₁, and a layer of cladding material that surrounds the core. The cladding comprises approximately pure silica, whose refractive index is n₂. Between the core and the cladding, the fiber further includes first and second annular rings of doped silica. The first annular ring has a width of 4.5±1.5 microns, is doped with fluorine, and has a refractive index n₃. The second annular ring is doped with germanium and has a refractive index n₄. These indexes are constrained by the following equations:; $PTEXTPDAT0.45(n/PDATHILSBPDAT1/PDAT/SB/HILPDAT\−n/PDATHILSBPDAT2/PDAT/SB/HILPDAT)/n/PDATHILSBPDAT2/PDAT/SB/HILPDAT0.58;/PDAT/PTEXT$ ; $PTEXTPDAT\−0.09(n/PDATHILSBPDAT3/PDAT/SB/HILPDAT\−n/PDATHILSBPDAT2/PDAT/SB/HILPDAT)/n/PDATHILSBPDAT2/PDAT/SB/HILPDAT\−0.05;\; and/PDAT/PTEXT$ ; $PTEXTPDAT0.02(n/PDATHILSBPDAT4/PDAT/SB/HILPDAT\−n/PDATHILSBPDAT2/PDAT/SB/HILPDAT)/n/PDATHILSBPDAT2/PDAT/SB/HILPDAT0.28./PDAT/PTEXT$