Optical fiber, method for manufacturing same and optical transmission channel
AssigneeFurukawa Electric Co., Ltd.
InventorsShuhei Hayami, Mitsuhiro Kawasaki, Yohei Uchida
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Abstract
The present invention provides an optical fiber of which a zero dispersion wavelength falls within a range of between 1,250 nm and 1,350 nm inclusive, transmission loss at 1,550 nm is equal to or less than 0.185 dB/km, chromatic dispersion at 1,550 nm is within the range of 19±1 ps/nm·km, a dispersion slope at 1,550 nm is equal to or less than 0.06 ps/nm2·km, an effective area Aeff is equal to or more than 105 μm2, a cable cutoff wavelength λcc is equal to or less than 1,530 nm, polarization mode dispersion is equal to or less than 0.1 ps/km1/2, and a loss when the optical fiber is wound on a mandrel having an outer diameter of 20 mm is equal to or less than 10 dB/m.
Claims8
An optical fiber comprising:
- a first region provided in a center of the optical fiber, having a refractive index difference Δn1 relative to a refractive index n0 of silica and an outer diameter of a;
- a second region formed around said first region, having a refractive index difference Δn2 relative to the refractive index n0 of silica and an outer diameter of b;
- a third region formed around said second region, having a refractive index difference Δn3 relative to the refractive index n0 of silica and an outer diameter of c;
- a fourth region formed around said third region, having a refractive index difference Δn4 relative to the refractive index n0 of silica and an outer diameter of d;
- and
- a fifth region formed around said fourth region, having a refractive index difference Δn5 relative to the refractive index n0 of silica and an outer diameter of e,
- in which the refractive index differences Δn1 through Δn5 satisfy a relationship as follows:
- Δn2<Δn4<Δn3<Δn1
- Δn1, Δn2, Δn3, Δn4<0
- Δn5>0.
A method for manufacturing an optical fiber which includes:
- a first region provided in a center of the optical fiber, having a refractive index difference Δn1 relative to a refractive index n0 of silica and an outer diameter of a;
- a second region formed around said first region, having a refractive index difference Δn2 relative to the refractive index n0 of silica and an outer diameter of b;
- a third region formed around said second region, having a refractive index difference Δn3 relative to the refractive index n0 of silica and an outer diameter of c;
- a fourth region formed around said third region, having a refractive index difference Δn4 relative to the refractive index n0 of silica and an outer diameter of d, and
- a fifth region formed around said fourth region, having a refractive index difference Δn5 relative to the refractive index n0 of silica and an outer diameter of e,
- in which the refractive index differences Δn1 through Δn5 satisfy a relationship as follows:
- Δn2<Δn4<Δn3<Δn1
- Δn1, Δn2, Δn3, Δn4<0
- Δn5>0,
- a zero dispersion wavelength of the optical fiber falls within a range of between 1,250 nm and 1,350 nm inclusive,
- the first region has a germanium concentration of CGe1 (mol %) and a fluorine concentration of CF1 (mol %),
- the second region has a germanium concentration of CGe2 (mol %) and a fluorine concentration of CF2 (mol %),
- the third region has a germanium concentration of CGe3 (mol %) and a fluorine concentration of CF3 (mol %),
- the fourth region has a germanium concentration of CGe4 (mol %) and a fluorine concentration of CF4 (mol %), and
- the germanium concentrations CGe1 through CGe4 and the fluorine concentrations CF1 through CF4 satisfy a relationship as follows:
- −0.1<0.096×CGe1−0.398×CF1<0
- −0.5≦0.096×CGe2−0.398×CF2≦−0.2
- −0.4≦0.096×CGe3−0.398×CF3≦−0.1
- −0.5<0.096×CGe4−0.398×CF4<−0.1,
- said method wherein, in synthesizing soots which are to be said first through fourth regions, respective soot synthetic raw materials including silica are doped with predetermined amounts of germanium and/or fluorine to synthesize the soots, and
- in vitrification of the soots to form a transparent glass, the soots are sintered in an atmosphere including fluorine and/or chlorine.
Dependencies are inferred from the claim text.