The Furukawa Electric Co., Ltd.

Ryo Miyabe

Ryuichi Sugizaki

Keiichi Aiso

Yu Mimura

Naomi Kumano

Jiro Hiroishi

Kazunori Mukasa

Hiroshi Matsuura

Koichi Maeda

Tsunetoshi Saito

Katsunori Imamura

Kengo Watanabe

Yukihiro Tsuchida

Tomohiro Gonda

Shigeto Matsumoto

An optical fiber has a core to which chlorine is added and a clad to which fluorine is added, chlorine of 9000 to 13000 ppm is added to the core, a relative refractive index difference &#x394;1 of the core to a pure silica glass is 0.09 to 0.13%, a relative refractive index difference &#x394;2 of the clad to a pure silica glass is &#x2212;0.36 to &#x2212;0.17%, a difference (&#x394;1-&#x394;2) between the relative refractive index difference &#x394;1 of the core and the relative refractive index difference &#x394;2 of the clad is larger than or equal to 0.30%, a mode field diameter at wavelength 1.31 &#x3bc;m is 8.8 to 9.6 &#x3bc;m, and a stress difference occurring at an interface between the core and the clad is lower than or equal to 60 MPa.

Optical fiber and manufacturing method of optical fiber

A method of producing a glass preform including: forming a porous glass soot configured by an inner deposition soot deposited on a start material and an outer deposition soot deposited outside the inner deposition soot; and sintering, after the forming, the porous glass soot while doping with fluorine to form a glass body including an inner glass portion and an outer glass layer. An amount of the fluorine, with which the inner deposition soot is doped at the sintering, is equal to or more than 0 g/cmand less than an amount of the fluorine with which the outer deposition soot is doped.

Method of producing glass preform and optical fiber

A production method of an optical fiber preform includes first preparing a first preform having a plurality of glass preforms and a first cladding portion disposed between the plurality of glass preforms, and first arranging a second cladding portion to surround the first preform. At the first arranging, a material gas and a combustion gas are ejected from a burner to produce glass particles. The first preform and the burner are moved relative to each other in a longitudinal direction of the first preform. The glass particles are deposited on the first preform.

Production method of optical fiber preform, and production method of optical fiber

A multi-core amplification optical fiber includes a plurality of rare-earth-doped core portions and a cladding portion positioned at an outer periphery of the core portions and having refractive index lower than those of the core portions. When a doping concentration of the rare-earth of each of the core portions is 250 ppm to 2000 ppm, a relative refractive index difference of each of the core portions relative to the cladding portion is 0.5% to 2% at a wavelength of 1550 nm, and a core diameter of each of the core portions is 1 &#x3bc;m to 5 &#x3bc;m, a separation distance between each of the core portions and adjacent one of the core portions is set at equal to or larger than 30 &#x3bc;m and at equal to or smaller than 60 &#x3bc;m so that a light-crosstalk between the adjacent core portions is equal to or lower than &#x2212;30 dB.

Multi-core amplification optical fiber and multi-core optical fiber amplifier

An optical fiber includes a core region having a first refractive index and a cladding region having a second refractive index lower than the first refractive index on an outer circumference of the core region. The cladding region includes four holes formed to have a four-fold rotational symmetry with respect to a center axis around the core region in a longitudinal direction, such that a zero-dispersion wavelength is 900 nm to 1150 nm and a cutoff wavelength is equal to or shorter than 950 nm.

Optical fiber and optical waveguide

A polarization-maintaining optical fiber includes a core region and a cladding region formed around the core region. The cladding region has a refractive index lower than a refractive index of the core region. A refractive index profile of the core region is either one of a step shaped or a concave shaped. The cladding region includes two holes formed in such a manner that a shortest distance from the core region is virtually zero at locations in opposite to each other across the core region.

Polarization-maintaining optical fiber, method of manufacturing polarization-maintaining optical-fiber connecting portion, and polarization-maintaining optical-fiber connecting portion

A core region is doped with an impurity. A first cladding region is formed in a layered structure around the core region, including a microstructure. A second cladding region is formed in a layered structure around the first cladding region, including a homogeneous material. A relative refractive-index difference &#x394;between the core region and the second cladding region is equal to or more than 0.4% and equal to or less than 1.0%.

Optical fiber and waveguide

An optical fiber in which the macro-bending loss is lowered while an MFD is maintained large, and a waveguide including the optical fiber. The optical fiber includes a core region doped with an impurity; a first cladding region formed as a layer around the core region and including holes as microstructures; and a second cladding region formed as a layer around the first cladding region and made of a homogeneous material. A relative refractive-index difference &#x394;1 between the core region and the second cladding region is equal to or higher than 0.01% and lower than 0.3%. A total cross-sectional area of the holes in the first cladding region with respect to a total cross-sectional area of the core region, the first cladding region, and the second cladding region is equal to or smaller than 20%. A waveguide is formed using the optical fiber.

An optical fiber includes a core region and a cladding region formed on an outer circumference of the core region. The cladding region includes a plurality of holes arranged around the core region and has a refractive index lower than a refractive index of the core region. A zero dispersion wavelength of the optical fiber is shorter than 1150 nanometers. The optical fiber propagates a light having a wavelength longer than 1000 nanometers exclusively in a fundamental mode of LPmode. An effective core area of the optical fiber is equal to or smaller than 12.0 &#x3bc;mat a wavelength of 1064 nanometers.

Optical fiber and optical device

An optical fiber includes a core region and a cladding region. The cladding region includes a first cladding region on outer circumference of the core region, which includes a main-medium region and a sub-medium region having a refractive index lower than that of the main-medium region. The sub-medium region includes a plurality of inner sub-medium regions arranged along the outer circumference of the core region and a plurality of outer sub-medium regions arranged on outer of the inner sub-medium regions. The outer sub-medium regions have a lateral cross section larger than that of the inner sub-medium regions.

Optical fiber and optical transmission medium

An optical fiber includes a core region and a cladding region. The cladding region includes a first cladding region on an outer circumference of the core region, the first cladding region including a main-medium region and a sub-medium region having a refractive index lower than a refractive index of the main-medium region. The sub-medium region includes inner sub-medium regions arranged at four folds rotationally symmetric centering on the core region, and outer sub-medium regions arranged at four folds rotationally symmetric centering on the core region on an outer side of the inner sub-medium regions.

The present invention provides an optical fiber of a high nonlinear characteristic which has low dispersion values in a wide wavelength region in the vicinity of a wavelength of 1550 nm. An excellent optical signal processing apparatus is realized by using this optical fiber, such as an optical wavelength converter and a pulse compressor. The optical fiber has characteristics; a dispersion slope at the wavelength of 1550 nm of &#x2212;0.01 to 0.01 ps/nm/km, an absolute value of dispersion at the wavelength of 1550 nm of 10 ps/nm/km or less, and a nonlinear constant at the wavelength of 1550 nm of 30&#xd7;10/W or more. A polarization retaining maintaining members are uniquely applied.

Nonlinear optical fiber and optical signal processing apparatus using the optical fiber

An optical fiber includes a first core with a first refractive index located in a central portion of the optical fiber; a second core with a second refractive index located in an outer periphery of the first core; a third core with a third refractive index located in an outer periphery of the second core; and a cladding with a fourth refractive index located in an outer periphery of the third core, where among the refractive indices, the first one&#x3e;the third one&#x3e;the fourth one&#x3e;the second one. The absolute value of dispersion at the wavelength of 1550 nm is not more than 20 ps/nm/km. The effective area at the wavelength is not more than 15 &#x3bc;m. The nonlinear constant n/Aeff at the wavelength of 1550 nm is equal to or more than 25&#xd7;10/W.

Growing community of inventors

Tokyo, Japan

Ryo Miyabe