The Furukawa Electric Co., Ltd.

Masahito Morimoto

Kouki Sato

Kazutaka Nara

Haruki Ogoshi

Haruki Urabe

Tsunetoshi Saitoh

Masato Shiino

Hajime Kazami

Katsuki Suematsu

Tsunetoshi Saito

Masateru Tadakuma

Masao Shinoda

Kengo Watanabe

Mitsuhiro Iwaya

Hijiri Nimura

Kohei Kawasaki

Koji Morimoto

Kazuhiro Toriumi

Taichi Tsuchiya

A light source for Raman amplification to Raman-amplify signal light includes: plural incoherent light sources that output incoherent light; plural pumping light sources that output second-order pumping light; an optical fiber for Raman amplification to Raman-amplify the incoherent light with the second-order pumping light, and outputs the amplified incoherent light; and an output unit connected to the optical transmission fiber, receiving the amplified incoherent light, and outputting the amplified incoherent light as first-order pumping light having a wavelength that Raman-amplifies the signal light to the optical transmission fiber.

Light source for Raman amplification, light source system for Raman amplification, Raman amplifier, and Raman amplifying system

A plurality of holes are formed in a ferrule. The holes are at sites penetrated by the tips of optical fibers. An opening is formed in the upper surface of the ferrule and an internal housing section is exposed from the opening. The housing section is at a site at which an optical fiber holding member is housed. The optical fibers are held by the optical fiber holding member. The optical fibers are multi-core fibers. In other words, the optical fibers have a specified axis of symmetry in a cross-section vertical to the longitudinal direction of the optical fibers and have orientation relative to a rotation direction having the longitudinal direction as the axis thereof.

Multi-core connector, connector, and connector connection mechanism

The present invention provides an optical communication method and an optical communication system in which eavesdropping is more difficult than in conventional techniques. An optical communication system in one embodiment of the present invention comprises: a photon pair generator which generates a correlated photon pair; a polarizer which is provided on an optical path of one photon of the correlated photon pair and direction of which is changeable based on information to be transmitted; a shutter which is provided between the photon pair generator and the polarizer on the optical path of the one photon of the correlated photon pair and which is capable of blocking the one photon of the correlated photon pair; and a photon detector which is provided on an optical path of another photon of the correlated photon pair.

Optical communication method and optical communication system

Two Mach-Zehnder optical interferometer circuits are accurately point-symmetrically connected to each other to form a first point-symmetrically connected optical interferometer circuit constituting a light input side circuit. Optical signals having a plurality of wavelengths are input to a light input terminal. A second point-symmetrically connected optical interferometer circuit having the same functional structure as the first point-symmetrically connected optical interferometer circuit is connected to a through port, which is an output terminal of the light input side circuit, as a first light output side circuit. A cross port, which is the other output terminal of the light input side circuit, is connected to a second light output side circuit having at least one of Mach-Zehnder optical interferometer circuits whose transmittance characteristics are different from those of the Mach-Zehnder optical interferometer circuits.

Broadband wavelength multiplexing and demultiplexing filter and optical splitter with optical signal multiplexing and demultiplexing function

An optical waveguide comprising a core and a clad characterized in that a desired part is heated and transited to machining strain release state, the part transited to the machining strain release state is curved with a specified bending radius and transited to machining strain state. That part of the optical waveguide is heated to a temperature within a range between the bending point and softening point and transited to machining strain state. The optical waveguide is an optical fiber having the outer diameter not shorter than 50 &#x3bc;m. The optical waveguide has the outer diameter not shorter than ten times of the mode field diameter of the optical waveguide. The optical waveguide has a bending radius of 5.0 mm or less and difference equivalent of refractive index &Dgr;between the core and clad falls within a range of 0.8-3.5%.

Optical waveguide, optical waveguide module and method for forming optical waveguide

Two Mach-Zehnder optical interferometer circuitsandare accurately point-symmetrically connected to each other to form a first point-symmetrically connected optical interferometer circuitconstituting a light input side circuit. Optical signals having a plurality of wavelengths are input to a light input terminal. A second point-symmetrically connected optical interferometer circuithaving the same functional structure as the first point-symmetrically connected optical interferometer circuitis connected to a through port, which is an output terminal of the light input side circuit, as a first light output side circuit. A cross port, which is the other output terminal of the light input side circuit, is connected to a second light output side circuithaving at least one of Mach-Zehnder optical interferometer circuitsandwhose transmittance characteristics are different from those of the Mach-Zehnder optical interferometer circuitsand

There are provided a power supply device for an optical functional component that supplies power to the optical functional component with reliability for a long term and enables easy exchange of the optical functional component, and an optical functional module having such a power supply device, where the power supply device is provided with a reception electrode, a power supply electrode-that supplies power to the reception electrodewhile holding tight the reception electrodeon its side faces and thereby holding an optical functional component-detachably, and a protecting memberthat is made of an insulating material and surrounds the power supply electrode-to prevent current leaks, and the power supply electrode-is comprised of two bent metallic members (-and-B) which are in intimate contact with the reception electrodeby elasticity.

Functional optical module

The invention comprises three parts: The first parts provides a miniaturized functional optical module, which is provided with a lens-exchange type collimator enabling rapid and easy exchange of an optical functional component and/or lenses and being compact in size and excellent in durability. The second part provides a power supply device for an optical functional component that supplies power to the optical functional component with reliability for a long term and enables easy exchange of the optical functional component, and an optical functional module having such a power supply device. The third part provides an optical switch compact in size and greatly easy in handling, which is provided with a connector module having a plurality of optical fibers for light-beam input, a plurality of optical fibers for light-beam output corresponding to the plurality of optical fibers and a light-beam reflecting member.

First and second optical fibers are opposed to each other, between which first and second lenses constituting a lens system having an optical axis coincident with those of the optical fibers are arranged with a gap therebetween in the direction of the optical axis. The actuators, ect are used to move the first and second lenses with electrostatic forces, in opposite directions along the optical axes of the optical fibers by the same amount at the same time. Thereby, the spot size of the light incident on the optical fiber on the reception side is changed while maintaining the light propagating between the first optical fiber and the second optical fiber point-symmetric in mode field shape. This changes the coupling efficiency between the first optical fiber and the second optical fiber, allowing an adjustment in light power.

Variable optical attenuator

An optical attenuator has first and second lenses provided individually on the respective end faces of first and second optical fibers that are opposed to each other across a space, and a shutter plate interposed between the lenses. The distance between the shutter plate and the second lens and a mode-field radius of propagating light on the second-lens-side surface of the shutter plate are set so that the respective signs of the real and imaginary parts of an evaluation function, representing a diffraction pattern of the propagating light that propagates from the first optical fiber to the second optical fiber, are inverted 60 times or more when a variable of the evaluation function is changed within an evaluation range.

The silicon substrate is masked on one surface of the silicon substrate where structures like combs and beams of comb drive are not to be formed on the other surface. The unmasked areas are then etched followed by masking areas on the other surface corresponding to the structures. Finally, the unmasked areas on the other surface are again etched by anisotropic reactive ion etching to form the structures.

Silicon device manufacturing method, silicon device, and optical component

There is provided an optical telecommunications method that can externally modulate a plane of polarization without producing any null point. According to the invention, in an optical telecommunications system for externally modulating the plane of polarization of the light being transmitted through an optical fiber for the transmission of a polarized wave signal by externally applying a signal to modify the state of polarization, the source of light for the transmission of a polarized wave signal is a fiber ring laser.

Growing community of inventors

Tokyo, Japan

Masahito Morimoto