Hitachi, Ltd.

Other

Nippon Telegraph and Telephone Corporation

Hitachi Cable, Inc.

Hitachi Tohbu Semiconductor, Ltd.

Hrein Energy, Inc.

Ichikawa, Masaru

Satoru Kikuchi

Shinji Tsuji

Takeshi Kato

Kimio Tatsuno

Masato Shishikura

Satoshi Aoki

Hitoshi Nakamura

Masahiro Aoki

Yoshitada Oshida

Masahiro Ojima

Kazumi Kawamoto

Kenji Uchida

Kazuyuki Fukuda

Shinichi Nakatsuka

Ryuta Takahashi

Hiroshi Naka

Misuzu Sagawa

Toshinori Hirataka

Masaru Ichikawa

Tatsuo Teraoka

Koji Yoshida

Katsumori Tanabe

Toshiyuki Mogi

Masashi Sakuramoto

Yoichi Yasuda

Yukimitsu Mita

The efficiency of dehydrogenation and that of hydrogenation are improved. A hydrogen generator for generating hydrogen by dehydrogenation of organic hydrides in the presence of a catalyst is characterized by comprising a reactor vessel () of a multi-tubular structure having a region () for supplying fuel to generate heat necessary for dehydrogenation, the region containing a combustion catalyst for combusting fuel, and a region () containing a dehydrogenation catalyst necessary for dehydrogenation, the regions being arranged radially side by side with a wall separating them. A hydrogenation apparatus which synthesizes organic hydrides by way of hydrogenation of unsaturated hydrocarbons in the presence of a catalyst is characterized by comprising a reactor vessel () of a multi-tubular structure having a region () for removing the heat generated by hydrogenation and a region () containing a hydrogenation catalyst necessary for hydrogenation, the regions being arranged radially side by side with a wall separating them.

Hydrogen generator and hydrogenation apparatus

In aiming at cost lowering of an optical module and an optical transmission apparatus and with the objective of providing a semiconductor light receiving element that has a good coherence with the other edge emitting/incidence type optical devices and is capable of performing the positioning easily and with a high accuracy, in the edge emitting/incidence type light receiving element in which the light absorbing layer has been formed, the space region is formed so as to provide at least 100 &mgr;m of the marker detecting region , thereby facilitating detection of marker on the optical device and executing the positioning of the light receiving element with a high accuracy, the space region resulting from eliminating a part of the light absorbing layer that absorbs the detection light of the light receiving element, the transmission amount of the detection light toward the marker detecting region that is parallel to a primary plane being equal to 30% or higher, the detection light having penetrated and transmitted the primary plane of the light receiving element.

Semiconductor photodetector and optical transmitting device

An optical communication equipment includes a semiconductor laser element, an image-forming element, an optical fiber and a substrate for mounting the semiconductor laser element, the image-forming element and the optical fiber. An optical output of the semiconductor laser element is adapted to be provided to the optical fiber via the image-forming element. The image-forming element is mounted in a V-groove formed in the substrate and having a substantially &ldquo;V&rdquo;-shaped cross-section. A shortest distance between a light spot of the semiconductor laser element and an optical axis of the image-forming element is 1 mm at most and the image-forming element substantially satisfies the sine condition.

Optical communication equipment and optical communication network equipment

An optical assembly has a substrate and an optical device chip. On mutually opposed surfaces of the optical device chip and the substrate, indexes having slope faces are formed. Index passage alignment is performed by using the indexes as positioning reference and by using image measurement.

Alignment of an optical assembly

An optical assembly structure includes, a semiconductor element generating a large amount of heat and a high impedance optical element which are to be mounted, with low optical loss on the same semiconductor substrate which has an optical waveguide formed thereon.The element generating a large amount of heat is mounted on a terrace of the semiconductor substrate directly or through an insulating layer having a thickness of submicron order, while the high impedance element is mounted in a groove which is etched into the semiconductor substrate to such an extent that the optical axis of the high impedance element mates with the optical axis of the optical waveguide layer formed on a recess in the semiconductor substrate. The optical axes can be adjusted independently for the respective elements. Alternatively, with a potential on the semiconductor substrate set equal to a supply voltage or a ground potential, a crystal substrate for a forward biased heat generating element is given the polarity opposite to that of a crystal substrate for a reverse biased element which may imply a problem of stray capacitance.

Hybrid optical integration assembly using optical platform

An optical fiber is held in a ferrule, and then the ferrule is located in a positioning groove formed in a substrate, thereby aligning the optical fiber with an optical device bonded to a surface of the substrate. Then, a lid is placed on the substrate in such a manner that the ferrule is located in a positioning groove formed in the lid and that the optical device is received in a cavity formed in the lid. The ferrule is thus held between the two grooves, and in this condition a resin is filled in the two grooves, thereby retaining the ferrule. Then, the lid is sealingly secured to the substrate. After these parts are thus assembled together, this assembly is put in dies, and then a package is molded.

Resin molded optical assembly

In order to position an optical semiconductor chip with high accuracy and without adjustment, a recess for controlling the displacement of the optical semiconductor chip is formed in a position in which the optical semiconductor chip on an optical element mounting substrate having an optical waveguide formed in the surface thereof is fixed.

Optical module having semiconductor elements fixedly mounted thereon

A semiconductor laser device is provided which is designed to prevent end surface optical damage, thereby permitting an increase in the output of the semiconductor laser. To achieve this, an active layer at the light emitting end surface portion of the semiconductor laser device is recessed inwardly by a distance between 50 nm and 300 nm (depending on the amount of etching) from the end surfaces of the crystal layers lying on both sides of the active layer. The recess serves to improve the heat dissipation of the active layer portion. This results in improving the amount of light output of the semiconductor laser which is possible without causing optical damage. A method for making the device is also provided. This method permits achieving the above-noted advantages simply by adding an etching step to the conventional semiconductor laser fabrication process, without requiring special equipment or technique.

Semiconductor laser device and a method for the manufacture thereof

Growing community of inventors

Kokubunji, Japan

Satoru Kikuchi