The Furukawa Electric Co., Ltd.

Yuki Taniguchi

Ryuichi Sugizaki

Takeshi Yagi

Masanori Takahashi

Yoshihiro Emori

Atsushi Oguri

Jiro Hiroishi

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 for Raman amplification amplifies a signal light with a pumping light. A chromatic dispersion at a wavelength of 1,550 nm is in a range between &#x2212;70 ps/nm/km and &#x2212;30 ps/nm/km. Raman gain efficiency with a pumping light of 1,450 nm is equal to or more than 5 (W&#xd7;km). Nonlinear coefficient at the wavelength of 1,550 nm is equal to or less than 5.0&#xd7;10W. Zero-dispersion wavelength is neither at a wavelength of the signal light nor at a wavelength of the pumping light. Cut-off wavelength is equal to or less than the wavelength of the pumping light.

Optical fiber for Raman amplification, optical fiber coil, Raman amplifier, and optical communication system

An optical fiber has a Raman gain efficiency with a pump power at 1450 nanometers of equal to or more than 4 m/W, and a ratio of a nonlinear parameter &#x3b3; at a wavelength of 1550 nanometers to the Raman gain efficiency with a pump power of 1450 nanometers is equal to or less than 3.

Optical fiber, optical fiber module, and Raman amplifier

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.

Growing community of inventors

Tokyo, Japan

Yuki Taniguchi