The Furukawa Electric Co., Ltd.

Jiro Hiroishi

Masanori Takahashi

Ryuichi Sugizaki

Naomi Kumano

Ryo Miyabe

Yuki Taniguchi

Hideaki Tobioka

Takeshi Yagi

Takashi Inoue

Shu Namiki

Masateru Tadakuma

Shunichi Matsushita

Shigehiro Takasaka

Koji Igarashi

An optical regeneration system for regenerating a degenerated signal light, comprising a regeneration device having at least one of a soliton converter, a pulse roller, a Kerr-shutter and a soliton purifier. The solilton converter uses an anomalous-dispersion fiber (ADF) having a fiber length up to three times the soliton frequency, and the pulse roller is provided with a pulse roller fiber having high non-linear characteristics. The Kerr-shutter comprises an optical LO (local oscillation) generator for generating an optical LO on an OPLL (optical phase locked loop), a phase comparator for detecting the phase difference between an externally-input signal light and an optical LO, and a control unit for regulating the repeated frequency of an optical LO based on the phase difference. The soliton purifier has a soliton fiber disposed between two optical fibers.

Wavelength division multiplex optical regeneration system and wavelength division multiplex optical regeneration method

A core includes a center core region, a core layer that is formed around the center core region and that has a refractive index lower than that of the center core region, and at least one buffer core layer that is formed between the center core region and the core layer and that has a refractive index lower than that of the center core region and higher than that of the core layer. A cladding is formed around the core layer and that has a refractive index lower than that of the center core region and higher than that of the core layer. An effective core area at a wavelength of 1550 nm is equal to or smaller than 18 &#x3bc;m.

Nonlinear optical fiber, nonlinear optical device, and optical signal processing apparatus

An optical fiber module includes an optical fiber that transmits a light and a holding unit that holds the optical fiber in a state in which the optical fiber is stretched in its longitudinal direction to change optical characteristics of the optical fiber.

Optical fiber module and optical device

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 wavelength converter inputs signal light and pumping light into an end of the highly nonlinear optical fiber to obtain converted light of the signal light from the other end of the highly nonlinear optical fiber. In the optical fiber wavelength converter, a wavelength &#x3bb;p of the pumping light is set within a range from &#x3bb;&#x2212;1 nanometers to &#x3bb;+1 nanometers, where &#x3bb;is a zero-dispersion wavelength of the highly nonlinear optical fiber, an absolute value of a dispersion slope of the highly nonlinear optical fiber with the wavelength &#x3bb;p is not more than 0.02 ps/nm/km, a nonlinear coefficient &#x3b3; of the highly nonlinear optical fiber with the wavelength &#x3bb;p is not less than 10/W/km, and a change in a conversion bandwidth D defined as D=|&#x3bb;p&#x2212;&#x3bb;s| is not more than 30 percent at variable environmental temperatures ranging from 0&#xb0; C to 40&#xb0; C.

Optical fiber wavelength converter

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.

Optical fiber having high nonlinearity

A highly nonlinear optical fiber includes a core, a cladding surrounding the core, and a coating covering the cladding. A bending loss at a wavelength of 1550 nanometers with a bending diameter of 20 millimeters is equal to or less than 0.01 dB/m. A nonlinear coefficient at the wavelength of 1550 nanometers is equal to or more than 10 Wkm. A cut-off wavelength is equal to or less than 1530 nanometers. A zero dispersion wavelength is in a range between 1400 nanometers and 1650 nanometers. A diameter of the coating is 125 micrometers with a tolerance of &#xb1;5 percent.

Highly nonlinear optical fiber and highly nonlinear optical fiber module

Disclosed is a nonlinear dispersion-shifted optical fiber, wherein a charomatic dispersion at a wavelength of 1550 nm is equal to a set value required for optical signal processing utilizing a nonlinear phenomenon, a dispersion slope at a wavelength of 1550 nm falls within a range of 0.001 to 0.1 ps/nm /km, a margin of fluctuation of the charomatic dispersion in a longitudinal direction of the optical fiber at a wavelength of 1550 nm falls within a range of 0.01 to 3 ps/nm/km, and a nonlinear constant n /A at a wavelength of 1550 nm is not smaller than 15&times;10 /W.

Nonlinear dispersion-shifted optical fiber, optical signal processing apparatus using said optical fiber and wavelength converter using said optical fiber

Growing community of inventors

Tokyo, Japan

Jiro Hiroishi