Hitachi Chemical Company, Ltd.

Rei Yamamoto

Nobuo Miyadera

Toshihiro Kuroda

Shigeyuki Yagi

Tomonori Seki

Michiaki Yajima

Tooru Yoshikawa

Atsushi Fujita

Noriji Tashiro

A heat radiation sheet having high heat-radiation property and excellent handleability and having sheet properties permitting the sheet to cope with changes in use temperature thereof. Also provided is a heat radiation device using the sheet. The heat radiation sheet comprises: a binder component comprising: (A) a thermoplastic rubber component; (B) a thermosetting rubber component; and (C) a thermosetting rubber curing agent crosslinkable with the thermosetting rubber component (B); and an anisotropic graphite powder oriented into a specified direction in the binder component.

Heat radiation sheet and heat radiation device

The thermal conductive sheet of the present invention includes a base sheet and, on one surface of the base sheet, a metal foil (C) that has a thickness of from 1 to 30% of a thickness of the base sheet. The base sheet includes a binder component (A) that exhibits elasticity at room temperature and a graphite powder (B) that has anisotropy, and the graphite powder (B) is oriented in a thickness direction.

Thermal conductive sheet, method of producing thermal conductive sheet and heat releasing device

An optical device to be connected to an optical fiber and an optical system in which the optical fiber is fixed to the optical device are provided, which optical device and optical system can restrict variations in a distance between inclined surfaces for supporting the optical fiber, and can enhance a productivity of the optical device and system. The optical system according to the present invention is, for example an optical multiplexer/demultiplexer having an optical device according to the present invention, which device has a substrate () with a crystal axis, and a groove () for supporting an optical fiber (). The groove () has a pair of opposing inclined surfaces () for supporting the optical fiber (), and a recess () formed between the pair of opposing inclined surfaces ().

Optical device, optical system, and method of manufacturing optical device

Provided is a light branching optical waveguide including: at least one incident light waveguide (A) optically connected to one end of a multi-mode optical waveguide; and output light waveguides (B) larger in number than the incident light waveguide (A) optically connected to the other end thereof, the light branching optical waveguide being characterized in that: an intensity distribution of light incident from at least one optical waveguide (a) out of the incident light waveguide (A) on the multi-mode optical waveguide at a connecting surface of the incident light waveguide (A) and the multi-mode optical waveguide is asymmetric with respect to a geometrical central axis of the optical waveguide (a); and an extended line of the geometrical center axis of the optical waveguide (a) does not coincide with a geometrical central axis of the multi-mode optical waveguide. Accordingly, it is possible to obtain a low-loss light branching optical waveguide having a reduced branch loss and a reduced variation in branching ratio, and further to obtain a light branching optical waveguide having small wavelength dependence as well as a reduced branch loss and a reduced variation in branching ratio.

Light branching optical waveguide

An optical waveguide structure comprises a substrate () having first and second groove arrays (), including grooves (--), and an optical waveguide (), having cladding and core () layered on the substrate between the groove arrays to vertically align the core with cores () of optical fibers () positioned on the grooves. The waveguide has at least one first port () aligned with a groove () of the first groove array and at least one second port () aligned with a groove () of the second groove array. The number of second ports is equal to or greater than that of the first ports. A ratio of the number of grooves of the second groove array relative to the number of grooves of the first groove array is less than a ratio of the number of the second ports relative to the number of first ports.

Optical waveguide structure, optical-waveguide-type optical module and optical fiber array

An optical system comprising a substrate and an optical waveguide which is formed on the substrate and to which optical fibers are optically coupled. The optical waveguide has a plurality of straight core portions which obliquely intersect each other. The substrate has positioning sections for positioning a plurality of optical fibers optically coupled to two or more of the plurality of the core portions, the positioning sections having grooves on which the respective optical fibers are supported. When the plurality of optical fibers are supported on the respective grooves, offsets between centers of the plurality of the core portions and respective centers of the plurality of the optical fibers coupled to the core portions are equal to or less than 5 &#x3bc;m.

Optical system and method of manufacturing the same

The present invention disclosed is an optical waveguide structure that has a first waveguide provided with the opposite ends A and B, a second waveguide with the opposite ends C and D, a third waveguide with the opposite ends E and F, and a coupling waveguide having its first beam incoming/outgoing end connected to the end B of the first waveguide and its second beam incoming/outgoing end connected to the end C of the second waveguide and the end E of the third waveguide. The optical waveguide is characterized in that the first waveguide and the coupling waveguide are longitudinally dimensioned so that light beam at its peak of light intensity can transit the point of axial mal-alignment at the end A of the first waveguide and further transit the axial zone at the second beam incoming/outgoing end of the coupling waveguide.

Optical waveguide structure including at least first, second and third waveguides and coupling waveguide

An optical device is provided to prevent a dicing blade form being clogged when a wafer is cut by means thereof. Further, an optical device is provided to the present invention can prevent unnecessary expansion of a resin used in the optical device. The present invention relates an optical device having a substrate and an optical waveguide layer laminated thereon. The optical waveguide layer has a first lateral surface connected to an optical fiber or an optical fiber array and a second lateral surface not connected to the same. The substrate has a lateral surface disposed on the same side as that of the second lateral surface of the optical waveguide layer. At least a portion of the second lateral surface of the optical waveguide layer is disposed in a plane different from the lateral surface of the substrate so that an exposed area of the substrate is formed between the second lateral surface of the optical waveguide layer and the lateral surface of the substrate.

Optical device

An optical reflector, an optical multiplexer/demultiplexer device and an optical system which can allow more flexible arrangement of an optical filter thereof, and enhance performance of wavelength division multiplexing communication thereof are provided. An optical reflector according to the present invention comprises a first and second optical fiber, each being connected to one side of an optical propagating region such as a rod lenscausing optical strength distributions depending on respective wavelengths of lights to be propagated in the optical propagating region; a mirrordisposed on the other side of the optical propagating region; and an optical filterdisposed between the first and second optical fibersand the mirrorThe optical filteris reflected a light having a first wavelength and allows another light having a second wavelength to be transmitted therethrough; and the mirroris reflected the light having the second wavelength, so that the lights having the first and second wavelengths are propagated between the first optical fiberand the second optical fiber

Optical reflector, optical system and optical multiplexer/demultiplexer device

The present invention provides an optical system with waveguides, which comprises first, second and third optical input/output means (), fourth and fifth multi-mode optical waveguides () each capable of propagating light with plural propagation modes, and optical-filter mounting means () for mounting an optical filter () between the fourth and fifth multi-mode optical waveguides () across a traveling direction of light in the fourth and fifth multi-mode optical waveguides (). The first optical input/output means () is connected to an end face of the fourth multi-mode optical waveguide () on a side thereof opposite to the optical-filter mounting means (). Each of the second and third optical input/output means () is connected to an end face of the fifth multi-mode optical waveguide () on a side opposite to the optical-filter mounting means (). Respective widths in a direction orthogonal to the light-traveling direction of the fourth and fifth multi-mode optical waveguides () are different from each other.

Optical system with optical waveguides

An optical directional coupler () comprises first and second straight optical waveguides () having respective cores () extending longitudinally close to each other to form an optical coupler portion, and a tapered optical waveguide () having a core () connected to the core () of the first straight waveguide (). The core () of the first straight waveguide () has a centerline (). A width of the core () of the tapered waveguide () becomes narrow toward the first straight waveguide () and a profile of the tapered waveguide () is asymmetric relative to the centerline () of the core () of the first straight waveguides ().

Optical directional coupler

A curved optical waveguide comprising a core and a clad, characterized in that: the core shape of the curved optical waveguide has no reversal of a curvature on a halfway; and curvatures at both ends of the curved optical waveguide gradually approach zero. A curved optical waveguide comprising a core and a clad, characterized in that: the core shape of the curved optical waveguide has no reversal of a curvature on a halfway; a curvature at one end of the curved optical waveguide gradually approaches zero; and a radius of curvature at other end is finite. An optical waveguide comprising such a curved optical waveguide and an optical waveguide having a different core shape optically connected with the former, and an optical device using such a curved optical waveguide.

Curved optical waveguide and optical device

An optical waveguide structure has a single port on one input/output side, a plurality of ports on another input/output side and an S-curve optical waveguide portion arranged on the outermost side of the waveguide structure and including a first circular arc optical waveguide portion and a second circular arc optical waveguide portion connected thereto. The waveguide portion also has a third circular arc optical waveguide portion extending from a first splitting/coupling point side in the first circular arc waveguide portion toward the plural/ports side and having a curvature inverted relative to the first circular arc optical waveguide portion. At the first splitting/coupling point, a tangential line of the first circular arc optical waveguide portion and a tangential line of the third circular arc optical waveguide portion are parallel to and spaced from each other.

Optical waveguide structure

The invention is directed to an optical waveguide that reduces an excess loss caused in a curved waveguide region by a deviation of the center axis of a beam propagating mode from the center axis of the optical waveguide. The optical waveguide has its part curved, and assuming that the shortest distance from a certain point of a convex edge of the curved portion to a concave edge is a waveguide width at that point, the optical waveguide has its width progressively reduced from the maximum waveguide width in the midst of the curved portion toward the opposite ends of the curved portion.

Optical waveguide

The present invention relates to a curved optical waveguide which is free of any axis-deviation structure in the middle of the waveguide and which has a sigmoidal core shape, wherein the curvature thereof at one end is zero and the curvature thereof at the other end is finite (&#x3e;0) and the use of such a curved optical waveguide permits the reduction of optical loss at the connected portions to the lowest possible level even when it is applied to, for instance, an optical splitter or a directional coupler and the curved optical waveguide of the present invention can provide an optical waveguide which never requires the use of any offset.

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Tsukuba, Japan

Rei Yamamoto