The Furukawa Electric Co., Ltd.

Atsushi Umeda

Ryuichi Sugizaki

Youichi Akasaka

Shiro Nakamura

Kunio Kokura

Jun Ishiguro

Akira Oyobe

Hiroshi Raijo

Nobutaka Fuke

The present invention provides a variable optical dispersion compensating module comprised of (a) an optical dispersion compensating unit having an input optical switch, an optical dispersion compensating fiber, connected to the optical switch, having a predetermined optical dispersion amount, a bypass path for bypassing the optical dispersion compensating fiber, and an output optical switch connected to the optical dispersion compensating fiber and the bypass path, (b) an optical dispersion compensating circuit with at least one of the unit connected in series, and (c) an optical attenuator provided, in the direction of an optical path, after the input optical switch or before the output optical switch of the optical dispersion compensating circuit.

Variable optical dispersion compensating module

There is provided a dispersion compensating fiber comprising a center core in which a first dopant is doped substantially uniformly, an outer core provided at the outer periphery of the center core, in which the first dopant is doped so as to decrease gradually toward the outer periphery, and a clad provided at the outer periphery of the outer core, in which a second dopant is doped. The second dopant of the outer core is doped so that the viscosity on at least the outer periphery side of the outer core is substantially equal to the viscosity of the clad.

Dispersion compensating fiber

The present invention is intended to provide a dispersion compensating optical fiber for wavelength division multiplex optical communication. A refractive index distribution of the dispersion compensating optical fiber is set to be W-shaped, an outside of a core is formed as an internal clad layer and the outside of the internal clad layer is formed as an outermost clad layer made of pure silica. Germanium for raising the refractive index by 2.8% in a specific refractive index difference is doped in the core, and fluorine is uniformly doped in the internal clad layer so that the refractive index is reduced by 0.45% in the specific refractive index difference. A diameter ratio of the core and the internal clad layer is set to be in a range of 1:1.5 to 1:4.0, a wavelength dispersion slope is set to be in a negative area, and dispersion is controlled to a negative high dispersion structure of -100 ps/km-nm or under.

Dispersion compensating optical fiber for wavelength multiplex

Growing community of inventors

Ichihara, Japan

Atsushi Umeda