The Furukawa Electric Co., Ltd.

Hitachi-high-technologies Corporation

Tohoku University

Hiroyuki Koshi

Takeshi Nakajima

Kazuhisa Kashihara

Naoki Hashizume

Hiroshi Kawashima

Kazutaka Nara

Toshinari Sakurai

Kanji Tanaka

Shiro Nakamura

Masakazu Matsui

Akihiro Shimase

Masako Kawarai

Isao Ohyama

Taiichi Otsuji

Takuya Komatsu

Katsumi Iwatsuki

Masafumi Yashima

Hirohito Yamada

Koji Horikawa

Isao Ooyama

A power system includes: a direct-current bus to which a power generation device and a plurality of power devices are connected; and a plurality of battery devices connected at predetermined intervals from one end of the direct-current bus to another end and configured to supply and receive power to and from the direct-current bus.

Power system

A cytometric mechanism includes: a flow path through which a cell suspension is made to flow; a liquid drive unit for sending the cell suspension which is in the flow path; and a computation unit for irradiating, with irradiation light from a light source, a cell suspension flowing through a flow cell, and for finding a cell survival rate in the cell suspension on the basis of a resulting forward scattered light intensity and transmittance and/or side scattered light intensity. The invention is provided with a calibration curve database for storing, in advance, respective calibration curves indicative of a relationship between viable cell concentration and forward scattered light intensity, a relationship between dead cell concentration and the transmittance, and a relationship between a cell survival rate and the side scattered light intensity.

Cytometric mechanism, cell culture device comprising same, and cytometric method

There is provided a wavelength variable light source system capable of changing wavelength and intensity of output signal light and of improving preset accuracy and stability of the wavelength and strength of the output signal light. The system determines the both or either one of a target value for controlling wavelength and a target value for controlling intensity of output signal light of a wavelength variable light source by correlating a combination of the target wavelength and the target light output intensity specified from a higher-level device and controls operation states of the wavelength variable light source so that output values of monitoring circuits for monitoring the operation state of the wavelength variable light source converge to the target values.

Wavelength variable light source system

An optical multiplexer/demultiplexer has a plurality of Mach-Zehnder optical interferometer multiplexing/demultiplexing circuits connected in plural stages, at least one of the plurality of Mach-Zehnder optical interferometer multiplexing/demultiplexing circuits including a first optical waveguide, a second optical waveguide disposed along the first optical waveguide, a first directional coupling portion that connects a first part of the first optical waveguide to a first part of the second optical waveguide, and a second directional coupling portion that connects a second part of the first optical waveguide to a second part of the second optical waveguide. A relationship among a coupling portion length L of at least one of the first and second directional coupling portions, a complete coupling length L of at least one of the first and second directional coupling portions and a lead portion coupling length L of at least one of the first and second directional coupling portions, is substantially:

Optical multiplexer/demultiplexer

An optical multiplexer/demultiplexer includes first and second directional coupling portions in which first and second optical waveguides are provided to transfer a light between the first and second optical waveguides. Lengths of the first and second optical waveguides have a difference (&Dgr;L). A product between the difference (&Dgr;L) and a refractive index (n) of the first and second optical waveguides approximates a product between a cross-propagation wavelength (&lgr;2) and a value (N&prime;) substantially equal to an integer (N), and a product between a through-propagation wavelength (&lgr;1) and the value (N&prime;)&plusmn;0.5. Power coupling ratio differences are at least approximately 1% and at most approximately 10%. Third power coupling ratios with respect to an average wavelength of the cross-propagation wavelength (&lgr;2) and the through-propagation wavelength (&lgr;1) are at least approximately 45% and at most approximately 55%.

Disclosed is a wavelength multiplexing module which provides stable multiplexed output power. The wavelength multiplexing module comprises a plurality of pumping sources for outputting lights of different wavelengths, and a wavelength multiplexer for multiplexing the lights output from the pumping sources. The wavelength multiplexer is provided with optical input sections for respectively receiving the lights output from the pumping sources. Respectively provided between the optical input sections and the pumping sources are depolarizers each of which causes a degree of polarization of the light output from an associated one of the pumping sources to approach zero. Each depolarizer has two polarization-maintaining optical fibers connected in series on an optical path in such a way that primary optic axes of the polarization-maintaining optical fibers obliquely intersect each other.

Wavelength multiplexing module with polarization maintaining fibers as depolarizers

An optical waveguide circuit capable of controlling polarization crosstalk is provided. An under cladding is formed on a silicon substrate ( ). A core is formed on the under cladding and has a waveguide structure in which one or more optical input waveguides ( ) arranged side by side are connected at their exit ends with a first slab guide ( ), which is connected at its exit end with an arrayed waveguide ( ) composed of plural channel waveguides ( ) that are different in length with the difference preset, and the arrayed waveguide ( ) is connected at its exit end with a second slab waveguide ( ), which is connected at its exit end with a plurality of optical output waveguides ( ). The top of the core is covered with an over cladding to form an optical waveguide portion ( ) composed of the under and over claddings and the core. A plurality of light beams having different wavelengths are entered to the core in the multiplexed manner, and the entered light beams are outputted separately on the basis of the wavelength. The claddings and the core are formed from silica glass. The birefringence B in the optical waveguide portion ( ) is set so as to satisfy &verbar;B&verbar;&gE;1.2&times;10 to reduce polarization crosstalk to &minus;20 dB or less.

Optical waveguide circuit

A hybrid optical waveguide circuit chip capable of predicting optical characteristics of a first optical waveguide circuit connected to optical elements where it is difficult to measure the optical characteristics. In the chip, a second optical waveguide circuit is disposed adjacent to the first optical waveguide circuit. One end face of the second optical waveguide circuit is terminated at one chip end face A of the chips, and at least one of the optical waveguide end faces at the other side of the second optical waveguide circuit is terminated at the other chip end face B of the chip, wherein the optical characteristics of the second optical waveguide circuit are measured, and the measured values are predicted as substantial optical characteristics of the first optical waveguide.

Hybrid optical waveguide circuit chip, and method for predicting the characteristics thereof

The present invention relates to an optical wavelength multiplexing and dividing device of an array waveguide type diffraction lattice, which is capable of separating and picking up wavelength-multiplexed signals of various wavelengths, which are used in optical transmissions. An input side slab waveguide ( ), a plurality of juxtaposed array waveguides ( ), an output side slab waveguide ( ) and a plurality of optical output waveguides ( ) are connected, in order, to the outgoing sides of a plurality of optical input waveguides ( ), thereby forming a waveguide pattern. The array waveguides ( ) are formed so as to have lengths different from each other to cause the phases of individual lights to be deviated after propagating through the respective array type waveguides ( ), wherein different lights as per wavelength are condensed at the incident ends ( ) of optical output waveguides by passing through the output side slab waveguides ( ) and are outputted through the optical output waveguides ( ). The incident ends ( ) of the optical output waveguides ( ) are provided at a light condensing predicted position of lights of the respective wavelengths where the lights are predicted to be condensed through the output side slab waveguide ( ), and the incident ends ( ) of the optical output waveguides ( ) are provided at a light condensing prediction corrected position where the light condensing position is shifted with respect to the light condensing predicted position.

Optical wavelength multiplexing and dividing device

An arrayed waveguide grating type optical multiplexer/demultiplexer includes input waveguides, an input-side slab waveguide, an arrayed waveguide diffraction grating, an output-side slab waveguide, and output waveguides. A junction between each input waveguide and the input-side slab waveguide is tapered such that the end portion of the input waveguide gradually widens in the width direction of the path toward the input-side slab waveguide, and includes two separate small-width waveguide portions arranged separately from the end portion of the input waveguide and extending in a line with taper of the tapered end portion, and a single large-width waveguide portion arranged separately from the small-width waveguide portions.

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Tokyo, Japan

Hiroyuki Koshi