Fujikura Limited

Afl Telecommunications Lcc

Shogo Shimizu

Ken Osato

Kuniharu Himeno

Akira Namazue

Kazuhiko Aikawa

Masakazu Nakayama

Takaaki Suzuki

Go Taki

Ryozo Yamauchi

Keiji Ohashi

Munehisa Fujimaki

Ryuji Suzuki

Yutaka Nagasawa

Okimi Mukai

An optical fiber cable includes: a sheath including recesses and protrusions that are alternately disposed in a circumferential direction on an outer circumferential surface of the sheath; a core that includes optical fibers and is accommodated in the sheath; tensile strength members embedded in the sheath; and a ripcord that is embedded in the sheath. A marking portion protruding outward in a radial direction is disposed in the sheath. The ripcord is disposed between the marking portion and the core.

Optical fiber cable

An optical fiber cable includes: a sheath; a core that is housed in the sheath and comprises optical fibers; tensile strength members embedded in the sheath; and ripcords embedded in the sheath. Recesses and protrusions are disposed alternately in a circumferential direction on an outer circumferential surface of the sheath. The recesses each include: two connecting portions respectively connected to radial inner ends of two adjacent protrusions; and a bottom surface positioned between the two connecting portions. In a transverse cross-sectional view, the ripcords are positioned inside some of the protrusions, and the tensile strength members are positioned inside the remaining protrusions.

An optical fiber cable includes: a sheath including recesses and protrusions that are alternately disposed in a circumferential direction on an outer circumferential surface of the sheath; a core that includes optical fibers and is accommodated in the sheath; and tensile strength members embedded in the sheath. The core is interposed between the tensile strength members in a transverse cross-sectional view. In the transverse cross-sectional view, the tensile strength members are embedded in portions of the sheath facing outward from the core in a first direction in which the two tensile strength members face each other in the transverse cross-sectional view.

An optical fiber cable includes: a sheath; and a core that is housed in the sheath and includes an intermittently-adhered optical fiber ribbon including optical fibers and adhesive portions for intermittently adhering the optical fibers in a longitudinal direction. Recesses and protrusions are disposed alternately in a circumferential direction on an outer circumferential surface of the sheath. The recesses each include: two connecting portions respectively connected to radial inner ends of two adjacent protrusions; and a bottom surface positioned between the two connecting portions.

An optical fiber cable includes: a core; an outer filling disposed outside the core; and a sheath that covers the core and the outer filling. The core includes: optical fibers; an inner filling; and a wrapping tube that wraps the optical fibers and the inner filling. The outer filling and the inner filling absorb water.

Optical fiber cable and method of manufacturing optical fiber cable

A dispersion compensating optical fiber for NZ-DSFs, includes: an uncovered dispersion compensating optical fiber; a double-layered resin coating disposed around the uncovered dispersion compensating optical fiber; and an outer coating layer having a thickness of 3 to 7 &#x3bc;m, containing silicone in an amount of 1 to 5% by weight, and disposed around the double-layered resin coating. The outer diameter of the uncovered dispersion compensating optical fiber is in a range from 90 to 125 &#x3bc;m, an outer diameter of the dispersion compensating optical fiber is in a range from 180 to 250 &#x3bc;m, and the amount of silicone contained in the outer coating layer is determined such that an adhesive property of the outer coating layer is 1 gf/mm or less.

Dispersion compensating optical fiber and dispersion compensating optical fiber module

A dispersion-compensated optical fiber which does not cause an increase in a loss if it is wound in a small reel and has a stable temperature characteristics is provided, wherein, in a wavelength range from. A dispersion-compensated optical fiber is formed such that, in at least a wavelength between 1.53 to 1.63 &#x3bc;m, a bending loss of with a 20 mm bending diameter is 5 dB/m or lower, a wavelength dispersion is &#x2212;120 ps/nm/km or lower, a cut-off wavelength under a usage condition is 1.53 &#x3bc;m or lower, an outer diameter of the cladding is 80 to 100 &#x3bc;m, an outer diameter of a coating is 160 to 200 &#x3bc;m, and a viscosity of a surface of a coating resin is 10 gf/mm or lower. It is set such that b/a is 1.5 to 3.5, c/b is 1.2 to 2.0, a radius of a core is 4 to 8 &#x3bc;m, &#x394;1 is +1.6% to +2.6%, &#x394;2 is &#x2212;0.30% to &#x2212;1.4%, and &#x394;3 is &#x2212;0.30% to +1.0%. Young's modulus of a first coating layer is 0.15 kgf/mm2 or lower and its thickness is 20 to 30 &#x3bc;m. Young's modulus of a second coating layer is 50 kgf/mm2 or lower and its thickness is 15 to 30 &#x3bc;m.

Dispersion compensating optical fiber

In fusion-splicing a dispersion compensating optical fiber having a negative dispersion slope, with a connection optical fiber having a different near field pattern from that of the dispersion compensating optical fiber, if for the connection optical fiber, one is selected such that a theoretical joint loss in a used wavelength, obtained from an overlap integral of a near field pattern of the dispersion compensating optical fiber after fusion splicing and a near field pattern of the connection optical fiber after fusion splicing is presumed to be 0.3 dB or less, in an unconnected state, a construction enabling connection at a low loss results.

Joint loss minimizing connection structure for dispersion compensating optical fiber

A dispersion compensating optical fiber includes an uncovered dispersion compensating optical fiber containing a core and a cladding, and a resin coating which is disposed around the uncovered dispersion compensating optical fiber, wherein the resin coating has an adhesive property of 10 g/mm or less, and which includes an outer coating layer which is formed to have a thickness of 3 &#x3bc;m or more, and the outer diameter of the uncovered dispersion compensating optical fiber is in a range from 90 to 125 &#x3bc;m, and the outer diameter of the dispersion compensating optical fiber is in a range from 180 to 250 &#x3bc;m.

A dispersion compensating fiber, which has a negative dispersion slope with a large absolute value while maintaining the absolute value of the chromatic dispersion, and which has sufficient dispersion slope compensation properties even for the non-zero dispersion shifted optical fiber requiring a large RDS for dispersion compensation. In this dispersion compensating fiber, the radius of a ring core region is set in a range from 6.7 &#x3bc;m to 10.7 &#x3bc;m, the radius ratio of a depressed core region relative to a central core region is set in a range from 2.0 to 3.0, and the radius ratio of the ring core region relative to the depressed core region is set in a range from 1.3 to 2.0, the relative refractive index difference of the central core region relative to the cladding is set in a range from +1.00% to +1.80%, the relative refractive index difference of the depressed core region relative to the cladding is set in a range from &#x2212;1.20% to &#x2212;1.50%, and the relative refractive index difference of the ring core region relative to the cladding is set in a range from +0.20% to +0.50%.

Dispersion compensating fiber and dispersion compensating fiber module

The present invention provides an optical transmission system that enables high-speed transmission of 40 Gb/s with low residual dispersion while maintaining the yield of a dispersion compensating fiber. In the present invention, the dispersion compensating fiber is connected to each span of an optical fiber for transmission. One set of an optical transmission path is formed by this optical fiber for transmission and the dispersion compensating fiber, and this one set of optical transmission path is connected in multiple stages and connected to a transmitter and a receiver. By setting the conditions of dispersion compensation in each span comparatively leniently, managing the residual dispersion of each transmission span, and suitably arranging each transmission span, an optical transmission system is composed in which adequate dispersion compensation is performed over the entire optical transmission path.

Growing community of inventors

Sakura, Japan

Shogo Shimizu