Mitsubishi Electric Corporation

Hoya Corporation

Mitsubishi Electric Research Laboratories, Inc.

Mitsubishi Denki Kabushiki Kaisha

Subaru Corporation

Yosuke Suzuki

Satoshi Nishikawa

Keisuke Kojima

Kyosuke Kuramoto

Shusaku Hayashi

Harumi Nishiguchi

Jonathan Klamkin

Masatsugu Kusunoki

Yingheng Tang

Yohei Hokama

Naoki Nakamura

Koichi Akiyama

Yoichiro Tarui

Eiji Yagyu

Hiroyuki Okazaki

Naoki Yasuda

Katsuomi Shiozawa

Kenichi Ohtsuka

Toshiyuki Oishi

Yasunori Tokuda

Go Sakaino

Yasuyuki Nakagawa

Yuichiro Okunuki

Hideo Sakai

Kunihiko Nishimura

Misao Hironaka

Kyozo Kanamoto

Takuma Nanjo

Hiromasu Matsuoka

Satoru Kawamoto

Yoshihiro Tawara

Keigo Fukunaga

Yoshinobu Hirokado

Ryoko Suzuki

Muneyoshi Suita

Akifumi Imai

Masayuki Shimura

Yuichiro Horiguchi

Takeo Shirahama

Takanori Mizuno

Tatsuo Omori

Hirofumi Imanishi

A semiconductor laser in which a PD unit monitoring an optical output is integrated is provided. A semiconductor laser () includes: a DFB unit including a back surface side first cladding layer (), a first diffraction grating layer (), a light emitting layer () having a first MQW structure and emitting a laser beam, a front surface side first cladding layer (), and a first contact layer () which are stacked; a DBR unit including a back surface side second cladding layer () having a resistivity higher than that of the back surface side first cladding layer (), a second diffraction grating layer () reflecting part of the laser beam toward the DFB unit, a first core layer () guiding a remnant of the laser beam and having an effective bandgap energy smaller than that of the first MQW structure, and a front surface side second cladding layer () having a resistivity higher than that of the front surface side first cladding layer () which are stacked; and a PD unit including a back surface side third cladding layer (), a second core layer () having a second MQW structure absorbing the remnant of the laser beam guided by the first core layer (), a front surface side third cladding layer (), and a second contact layer () which are stacked.

Semiconductor laser, semiconductor laser array and method of manufacturing semiconductor laser

A grating coupler having first and second ends for coupling a light beam to a waveguide of a chip includes a substrate configured to receive the light beam from the first end and transmit the light beam through the second end, the substrate having a first refractive index n1, a grating structure having curved grating lines arranged on the substrate, the grating structure having a second refractive index n1, wherein the curved grating lines have line width w and height d and are arranged by a pitch &#x39b;, wherein the second refractive index n2 is less than first refractive index n1, and a cladding layer configured to cover the grating structure, wherein the cladding layer has a third refractive index n3. The curves of the grating lines are constructed such that the emitting beam is shaped for efficient coupling to another optical component. The curves can also be tilted to reduce coupling back into the waveguide.

Grating coupler and integrated grating coupler system

An optical semiconductor device includes a semiconductor substrate, a first semiconductor layer provided on the semiconductor substrate, and a mesa waveguide provided on the principal surface of the first semiconductor layer. The semiconductor device also includes a buried layer covering the upper surface of the first semiconductor layer. Part of the upper surface of the first semiconductor layer is exposed. A mesa structure provided at the boundary between a part of the first semiconductor layer is covered with the buried layer and a part of the first semiconductor layer is exposed. One side of the mesa structure is covered with the buried layer, and the other side is exposed. The optical semiconductor device can reduce the generation of stress in the buried layer, for example, to suppress the occurrence of cracks in the buried layer and enhance the reliability.

Optical semiconductor device and method for manufacturing the same

An optical semiconductor device has a semiconductor laser which emits front-end-surface-side emergent light on the front end surface side and emits rear-end-surface-side emergent light on the rear end surface side, and a mount substrate having the semiconductor laser provided on its front surface. The rear-end-surface-side emergent light is emitted while having an emergence optical axis that extends away from the mount substrate with increase in distance from the rear end surface.

Optical semiconductor device

An engine air intake structure includes a partition plate and a valve. The plate partitions an air intake passage communicating with an intake port into first and second paths. The valve is disposed in the passage and secured to the shaft. A first path opening is changed variable by the valve. The structure also includes an opposing surface, a stepped surface, an extending surface and a measurement groove. The opposing surface is an inner wall surface of the passage and opposes an end away from the shaft when the opening becomes minimal. The stepped surface is located on the intake port side of the end of the valve at the minimal opening and stands erect from the opposing surface. The extending surface extends from the stepped surface toward the intake port. The measurement groove is formed in the extending surface and extends from the stepped surface toward the intake port.

Engine air intake structure

In a magnetic disk glass substrate manufacturing method, a main surface of a glass substrate is polished using a polishing liquid containing colloidal silica abrasive particles as polishing abrasive particles and a surface plate with a polishing pad, then the glass substrate is brought into contact with a liquid containing a coagulant so that the colloidal silica abrasive particles are coagulated, and then the colloidal silica abrasive particles coagulated are removed.

Method of manufacturing a glass substrate for a magnetic disk and method of manufacturing a magnetic disk

The present invention relates to a method for manufacturing a heterojunction semiconductor device including an AlGaN layer, the method including the steps of (a) forming a dummy electrode in a region where a gate electrode is arranged on the AlGaN layer, (b) depositing a dielectric film on the AlGaN layer by exposing side surfaces of the dummy electrode, using a device having anisotropy, (c) forming an opening in the dielectric film by removing the dummy electrode, and (d) forming the gate electrode that extends from inside the opening onto the dielectric film in a vicinity of the opening.

Method for manufacturing semiconductor device

An object of the invention is to effectively remove particles on the glass substrate surfaces, even in the case wherein abrasive particles having a small particle size is used in the polishing step of the glass substrate and a supersonic treatment is performed at a high frequency at the supersonic cleaning step after the polishing step. In a manufacturing method of a glass substrate for a magnetic disk comprising a polishing step for performing polishing of the glass substrate and a supersonic cleaning step for performing supersonic cleaning of the glass substrate after the polishing step, the polishing step uses abrasive particles having a particle size of 10 nm to 30 nm and a first supersonic cleaning is performed at a frequency of 300 kHz to 1,000 kHz to form secondary particles and then a second supersonic cleaning is performed at a frequency of 30 kHz to 100 kHz in the supersonic cleaning step.

Manufacturing method of a glass substrate for a magnetic disk

A method for manufacturing a glass substrate for a magnetic disk comprises a surface grinding step of processing a mirror-surface plate glass, having a main surface in the form of a mirror surface, to a required flatness and surface roughness using fixed abrasive particles. The method comprises, before the surface grinding step using the fixed abrasive particles, a surface roughening step of roughening the surface of the mirror-surface plate glass by frosting.

Method of manufacturing a glass substrate for a magnetic disk

A semiconductor device includes a submount; a semiconductor laser mounted on the submount via solder in a junction-down manner. The semiconductor laser includes a semiconductor substrate, a semiconductor laminated structure containing a p-n junction, on the semiconductor substrate, and an electrode on the semiconductor laminated structure and joined to the submount via the solder. A high-melting-point metal or dielectric film is located between the submount and the semiconductor laminated structure and surrounds the electrode.

Semiconductor device

A GaN laser, includes a coating film on a front end surface through which laser light is emitted. The coating film includes a first insulating film in contact with the front end surface and a second insulating film on the first insulating film. The optical film thickness of the second insulating film is an odd multiple of &#x3bb;/4 with respect to the wavelength &#x3bb; of laser light produced by the semiconductor laser. The adhesion of the first insulating film to GaN is stronger than the adhesion of the second insulating film to GaN. The refractive index of the second insulating film is 2 to 2.3 thick. The first insulating film is 10 nm or less. The first insulating film is an oxide film having a stoichiometric composition.

Semiconductor laser

A method of manufacturing a semiconductor device provides a semiconductor device with a gallium-nitride-based semiconductor structure that allows long-term stable operation without degradation in device performance. After formation of an insulation film on a surface other than on a ridge surface, an oxygen-containing gas such as O, O, NO, NO, or NOis supplied to oxidize a p-type GaN contact layer from the surface and to thereby form an oxide film on the surface of the p-type GaN contact layer. Then, a p-type electrode that establishes contact with the p-type GaN contact layer is formed by evaporation or sputtering on the oxide film and on the insulation film. Heat treatment is subsequently performed at temperatures between 400 and 700&#xb0; C. in an atmosphere containing a nitrogen-containing gas such as Nor NHor an inert gas such as Ar or He.

Method of manufacturing semiconductor device including gallium-nitride semiconductor structure and a palladium contact

The step of forming an opening in an insulating layer to expose a carbon nanotube layer is performed using two types of dry etching different from each other in conditions. In the first-stage dry etching step, a hole is formed in the insulating layer to such a depth as not exposing the carbon nanotube layer. Thereafter, in the second-stage dry etching step, a bottom surface portion of the hole is removed, thus exposing an upper surface of the carbon nanotube layer. A method of manufacturing an electron emission source capable of improving performance of an electron emission portion is thus obtained.

Method of manufacturing electron emission source

Growing community of inventors

Tokyo, Japan

Yosuke Suzuki