Nec Corporation

Fujitsu Corporation

Photonics Electronics Technology Research Association

Yutaka Urino

Tadahiko Hanada

Yoshinori Ohta

Tatsuya Usuki

Shigeru Nakamura

Takashi Saito

Kouichi Suzuki

Kiyoshi Fukuchi

Masashige Ishizaka

Shigeru Yoneda

Hikaru Kouta

Akio Furukawa

Mikio Oda

Kenji Mizutani

Ichiro Ogura

Itaru Nishioka

Taro Kaneko

Tomoki Saito

Masahiro Sakauchi

Daisuke Okamoto

Yuko Seki

Naoki Ofusa

A parallel computer system includes: direct links that forms a direct connection between a sending node and a receiving node, one-hop links that forms a connection between a sending node and a receiving node by way of a return node that is other than the sending node and the receiving node, and a communication control unit that, when transferring data from a sending node to a receiving node, selects the link that connects the sending node and the receiving node from among a link that uses only a direct link, a link that uses only a one-hop link, and a link that forms a connection combines and uses the direct link and the one-hop link.

Parallel computer system, method of controlling a parallel computer system, and a non-temporary computer-readable medium that stores a program

An optical transceiver according to an exemplary aspect of the invention includes an interferometer including an input-side optical coupler, an output-side optical coupler, and two arms through which to propagate light and disposed between the input-side optical coupler and the output-side optical coupler, adding a bias phase difference of approximately &#x3c0;/2+2n&#x3c0;, n representing an integer, between light beams propagating through the two arms; an optical phase modulator generating an optical signal obtained by modulating a phase of continuous wave light to be inputted depending on an electrical signal to be inputted; and an optical delay device making a difference in time for which the optical signal modulated by the optical phase modulator reaching the output-side optical coupler, wherein the optical phase modulator operates by changing carrier density in a silicon optical waveguide.

Optical transceiver

A network system comprises a plurality of nodes and a plurality of optical amplifiers. A first node comprises a first transmitter configured to send a wavelength-division-multiplexed optical signal and a first receiver configured to receive a wavelength-division-multiplexed optical signal, and the second node comprises a second transmitter configured to send a wavelength-division-multiplexed optical signal and a second receiver configured to receive a wavelength-division-multiplexed optical signal. The first and second transmitters are optically connected to an input of the first optical amplifier and an input of the second optical amplifier, respectively, and the first and second receivers are optically connected to an output of the first optical amplifier and an output of the second optical amplifier, respectively. The receivers each comprise a photoreceiver and a reception circuit. The photoreceiver is electrically connected, by flip chip connection, to a reception circuit. A reception circuit is configured not to comprise a transimpedance amplifier.

Network system

At least two light-emitting elements emit light to a branching device, and the branching device divides the light that entered into an input port into at least two and emits the light from M number of output ports. An optical modulator individually modulates the M number of light beams that were emitted. When a first light-emitting element driven normally fails, the first light-emitting element is stopped and a second light-emitting element that was stopped is driven, thereby maintaining the emission of the modulated M number of light beams.

Optical transmitter and optical communication device

An opto-electric integrated circuit includes an optical waveguide formed using a portion of an insulation layer on a silicon substrate to form a lower clad and using a portion of a semiconductor layer formed on the insulation layer to form a core. The opto-electric integrated circuit also includes an optical device connected to the optical waveguide, an electrical circuit connected to the optical device, a mesa-shaped connection section interconnecting the optical device and the electrical circuit, and an electrically conductive film formed in a region at least containing a flank surface of the connection section. The electrically conductive film is grounded while contacting the silicon substrate.

Opto-electric integrated circuit and optical interposer

A wavelength path communication node apparatus includes a wavelength path demultiplexer () which demultiplexes branched optical signals input to wavelength multiplexing ports into wavelength path signals, and outputs the wavelength path signals from wavelength demultiplexing ports corresponding to the respective wavelengths, a wavelength path multiplexer () which outputs wavelength path signals input to wavelength demultiplexing ports from wavelength multiplexing ports corresponding to the wavelengths of the wavelength path signals, a plurality of transponders () each of which converts a wavelength path signal input to a wavelength path transmission port into a client transmission signal to transmit the client transmission signal, and converts a received client reception signal into a wavelength path signal of a wavelength to output the wavelength path signal from a wavelength path reception port, a demultiplexing system optical matrix switch () which switches and connects the wavelength demultiplexing ports of the wavelength path demultiplexer and the wavelength path transmission ports of the transponders, and a multiplexing system optical matrix switch () which switches and connects the wavelength demultiplexing ports of the wavelength path multiplexer and the wavelength path reception ports of the transponders.

Wavelength path communication node apparatus, wavelength path communication control method, and recording medium

A light control element includes three or more silicon thin-film layers () placed on a first dielectric layer (), second dielectric layers () placed between the three or more silicon thin-film layers (), and a third dielectric layer () placed to surround the silicon thin-film layers and the second dielectric layers. The three or more silicon thin-film layers are arranged to partially overlap with one anther. In the part where the silicon thin-film layers overlap, the second dielectric layers are placed between the silicon thin-film layers. In the three or more silicon thin-film layers, the silicon thin-film layers adjacent to each other have different conductivity types.

Light control element and optical waveguide circuit

A wavelength routing system includes a plurality of nodes () and an array waveguide grating () having a routing property and optically connected to the plurality of nodes. Each of the nodes has a plurality of light sources (TLS) outputting lights at different wavelengths to the array waveguide grating, respectively, and a wavelength demultiplexer () having a periodic property, demultiplexing a light output from the array waveguide grating, and outputting demultiplexed lights. The wavelength demultiplexer is set a channel period which is different from that of the array waveguide, and which is more than or equal to a number of output ports of the wavelength demultiplexer.

Wavelength routing system

A fiber-type optical coupler has two optical fibers including a core on which a slanting Bragg diffraction grating is formed and a first cladding and a second cladding bordered with a boundary plane close to the core. The two optical fibers are placed by approximating the boundary plane almost contacting the core, making respective optical axes almost parallel and also making slanting directions of the respective Bragg diffraction gratings almost parallel. A wave vector of the slanting Bragg diffraction grating is located in a plane made by a normal set up on the boundary plane almost contacting the core and the optical axis of the core, and an angle_made by the wave vector and the optical axis is 0 degree &#x3c;_&#x3c;90 degrees. In addition, a refractive index of the second cladding is lower than that of the first cladding.

Method of manufacturing a fiber-type optical coupler with slanting bragg diffraction gratings

The present invention relates to a device and a method for monitoring each of the propagated light beams that are propagated in each waveguide of an arrayed waveguide device and a method of fabricating the device. In the prior art, problems were encountered in deriving monitor light and photodetecting the derived monitor light within the waveguide substrate. In the present invention, waveguide directional couplers are formed in the spaces between the arrayed waveguides to derive a portion of the propagated light as monitor light. Cavities are provided at the ends of auxiliary waveguides connected to the directional couplers, and monitor light is guideded into these cavities. The monitor light, after being reflected upward or downward of the substrate by optical path conversion elements installed inside the cavities, is photodetected by photodiodes. The optical path conversion elements can be fabricated by inserting metal bumps into the cavities and then forming the bumps with a mold.

Optical circuit element and production method therefor, array-form optical circuit element, optical circuit device using it

An optical coupler comprises a tapered waveguide formed so that a waveguide width may be narrower as going from a predetermined starting position toward an emission end of a light signal. A difference between a first coupling factor and a second coupling factor is set within a predetermined range. The first coupling factor is the coupling factor to a waveguide having the same width as that in a first position in an inherent mode in the case where the tapered waveguide is cut in the first position. A second coupling factor is the coupling factor to a waveguide having the same width as that in a second position where is separated at a predetermined distance from the first position along a direction toward the emission end in an inherent mode in the case where the tapered waveguide is cut in the second position.

Optical coupler

A fiber-type optical coupler has two optical fibers including a core on which a slanting Bragg diffraction grating is formed and a first cladding and a second cladding bordered with a boundary plane close to the core. The two optical fibers are placed by approximating the boundary plane almost contacting the core, making respective optical axes almost parallel and also making slanting directions of the respective Bragg diffraction gratings almost parallel. A wave vector of the slanting Bragg diffraction grating is located in a plane made by a normal set up on the boundary plane almost contacting the core and the optical axis of the core, and an angle &#x3b8; made by the wave vector and the optical axis is 0 degree&#x3c;&#x3b8;&#x3c;90 degrees. In addition, a refractive index of the second cladding is lower than that of the first cladding.

Fiber-type optical coupler with slanting Bragg diffraction gratings and optical parts and apparatuses using the same

A waveguide optical switch has a waveguide whose refractive index changes can be controlled by an electro-optic effect and an UV guide waveguide for coupling an ultraviolet radiation to the waveguide. A portion of the waveguide and a portion of the UV guide waveguide make up a directional coupler.

Optical waveguide device to be optically poled, method of manufacturing optical waveguide device to be optically poled, and method of optically poling optical waveguide device

An arrayed waveguide grating for easily changing the ratio of distribution of an optical signal into the main optical signal and the monitored optical signal is disclosed. In the device, an optical signal incident on an input waveguide is input into an arrayed waveguide via an input-side slab waveguide and is divided into main optical signals having different wavelengths in the arrayed waveguide with respect to a diffraction order m (natural number), and the divided optical signals are transmitted through an output-side slab waveguide and converged on output waveguides. The device has monitoring waveguides for monitoring optical signals having corresponding wavelengths of the main optical signals, where the monitored optical signals are diffracted in the arrayed waveguide with respect to a diffraction order m&plus;i or m&minus;i (i is a natural number), and the arrayed waveguide has a taper structure in the vicinity of the joint of the arrayed waveguide and the output-side slab waveguide, in which the width of each waveguide gradually changes along the direction of light transmission so as to adjust the ratio of distribution into the main optical signal and the monitored optical signal.

Arrayed waveguide grating having arrayed waveguide employing taper structure

An optical circuit device includes a directional coupling section and at least one diffraction grating. The directional coupling section is comprised of first and second optical waveguides and having a length n times (n is an integer equal to or larger than two) the minimum length required to completely couple light inputted to the first optical waveguide with the second optical waveguide. The diffraction grating is formed in the directional coupling section and has a specific reflection characteristic. When input light beams having different wavelengths are inputted to the input side of the first optical waveguide, light having a reflection wavelength in the diffraction grating is demultiplexed/outputted to the input side of the second optical waveguide. Light beams having other wavelengths are outputted to the output side of the first or second optical waveguide. When the light having the reflection wavelength in the diffraction grating is inputted through one of the output sides of the first and second optical waveguides from which the light beams having other wavelengths are not outputted, the light having the reflection wavelength input through the output side of the optical waveguide is multiplexed with the output light beams having other wavelengths.

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Tokyo, Japan

Yutaka Urino