Mitsubishi Denki Kabushiki Kaisha

Mitsubishi Electric Corporation

The Kansai Electric Power Co., Inc.

Tetsuya Yagi

Hitoshi Kagawa

Harumi Nishiguchi

Ryo Hattori

Yasuaki Yoshida

Tatsunori Okada

Mitsuie Matsumura

Zempei Kawazu

Takuji Sonoda

Shigeru Mitsui

Nobuyuki Kasai

Shinichi Sakamoto

Masahiro Mukai

Toshio Shinoki

Yoichiro Ota

Yasuhira Kikuoka

Jitsuji Otsuki

Akira Kusunoki

Yutaka Nagai

Junichi Horie

Yutaka Mihashi

Akihiro Shima

Yasuyuki Nakagawa

Misao Hironaka

Takashi Inaguchi

Takahiro Nakamoto

Hiromasu Matsuoka

Katsuki Hotta

Yasuhiro Kunitsugu

Masaki Kohno

Yoshihisa Tashiro

Masato Okada

Koji Ando

Sachiyo Kato

Tsuneo Okada

According to an electromagnetic switch of the present invention, a crossbar operating in conjunction with a movable core slides in response to magnetization or demagnetization of an operating coil to cause attraction or separation between a fixed contact point and a movable contact point on the supply-side and between a fixed contact point and a movable contact point on the load-side. The electromagnetic switch further includes a first crossbar sliding part and a second crossbar sliding part, as well as a first casing sliding part and a second casing sliding part that allow the first and second crossbar sliding parts to slide. A contact between the first casing sliding part and the first crossbar sliding part or between the second casing sliding part and the second crossbar sliding part causes the crossbar on the side of the movable core to be tilted in a direction opposite to the direction of gravity with respect to the horizontal.

Electromagnetic switch

A semiconductor laser has a reflectance of the front facet coating film or the rear facet coating film dramatically that decreases at wavelengths greater than a predetermined wavelength. This characteristic causes the loss of the semiconductor laser to dramatically increase at wavelengths greater than the predetermined wavelength. As a result, the oscillation wavelength of the semiconductor laser at high temperatures is clamped to around the predetermined wavelength.

Semiconductor laser having Fabry-Perot resonator

A semiconductor laser device has an n-GaAs substrate. On the n-GaAs substrate, by turns, are an n-AlGaInP cladding layer, an AlGaInP/GaInP MQW active layer, a p-AlGaInP first cladding layer, a single layer p-AlGaAs etching stopping layer, a p-AlGaInP second cladding layer with a stripe protrusion, and a p-GaAs contact layer. The portion, other than the stripe-form protrusion, of the p-AlGaInP second cladding layer is covered with an insulating film. The refractive index of the p-AlGaAs-ESL is nearly equal to the refractive index of each of the lower, first upper, and second upper cladding layers.

Semiconductor laser device

In fabricating a semiconductor laser producing light with a wavelength of 770 to 810 nm, impurities are introduced into an MQW active layer near a light emitting facet of the laser to form a disordered region constituting a window layer. Pump light is applied to the window layer to generate photoluminescence whose wavelength &#x3bb; dpl (nm) is measured. A blue shift amount &#x3bb; bl (nm) is defined as the difference between the wavelength &#x3bb; apl (nm) 0f photoluminescence generated by application of pump light to the active layer on the one hand, and the wavelength &#x3bb; dpl (nm) of photoluminescence from the window layer under pump light irradiation on the other hand. The blue shift amount &#x3bb; bl is referenced during the fabrication process in order to predict catastrophic optical damage levels of semiconductor lasers.

Method of fabricating semiconductor laser

A low reflective film is formed of, in sequence from a side in contact with a laser chip, a first dielectric film of a refractive index nand a thickness d, a second dielectric film of a refractive index nand a thickness d, a third dielectric film of a refractive index nand a thickness d, and a fourth dielectric film of a refractive index nand a thickness d, specifically, aluminum oxide AlOwith a refractive index n=1.638 is used for the first dielectric film, silicon oxide SiOwith a refractive index n=n=1.489 for the second and fourth dielectric films, tantalum oxide TaOwith a refractive index n=2.063 for the third dielectric film, respectively, resulting in a semiconductor laser device with a reflectance which is stably controllable.

Semiconductor laser devices

A semiconductor laser device includes a stacked structure. The stacked structure includes a first electrode, a substrate of a first conductivity type on the first electrode, a first cladding layer of the first conductivity type, an active layer, a second cladding layer of a second conductivity type opposite the first conductivity type, an insulating layer, and a second electrode. The second cladding layer includes at least first and second portions having thickness different from each other. The first portion is thicker than the second portion. The insulating layer is deposited on the second cladding layer but not on the first portion. The second electrode is electrically connected to the first portion. A product of a reciprocal of layer thickness and heat conductivity of the insulating layer is smaller than 4&times;10 W/(m K).

A heterojunction structure has an Al Ga As layer (0<x&lE;1), on which an Al Ga As layer (0&lE;y&lE;1 and y<x) is provided and having a band gap energy smaller than that of the Al Ga As layer and a valence band energy edge higher than that of the Al Ga As layer. When the Al Ga As layer is selectively etched, an Au electrode film is formed on a surface of the Al Ga As layer outside an etching region, a resist pattern is formed covering the Au electrode film and leaving exposed the etching region, and the Al Ga As layer is selectively removed by etching while irradiating with light, using an etching solution having a Fermi level higher than that of the Al Ga As layer.

Method for fabricating a semiconductor device

A bipolar plate is designed to provide a gas seal 16 around an electrode and gas seals 17a around fuel gas manifolds on the same plane and to separate the gas seal 16 and gas seals 17a around oxidant gas manifolds 4, 6 with hollowed parts on an anode electrode 25 side, and to provide the gas seal 16 and the gas seals 17b on a same plane and to separate the gas seal 16 and the gas seals 17a with hollowed parts on a cathode electrode 20 side. Also disclosed are sealing parts for the fuel side and the oxidant side of the fuel cell.

Fuel cell and sealing parts therefore

A bipolar plate is designed to provide a gas seal 16 around an electrode and gas seals 17a around fuel gas manifolds on the same plane and to separate the gas seal 16 and gas seals 17a around oxidant gas manifolds 4, 6 with hollowed parts on an anode electrode 25 side, and to provide the gas seal 16 and the gas seals 17b on a same plane and to separate the gas seal 16 and the gas seals 17a with hollowed parts on a cathode electrode 20 side.

Fuel cell and its bipolar plate

A superlattice layer is introduced in the ridge stripe structure of a buried ridge type semiconductor laser. This superlattice layer captures and redirects the propagation of a dislocation which occurs due to a shearing stress created in the crystalline structure during either an epitaxial growth or a cooling process following the epitaxial growth. This superlative layer eliminates the possibility of a through dislocation penetrating the laser active region under the ridge stripe structure so that optical loss along a waveguide can be avoided. Consequently, a semiconductor laser with a long lifetime and superior characteristics is obtained.

Semiconductor laser

A semiconductor device having a gate electrode having a leg with two mutually offset portions is formed by successively depositing on a semiconductor substrate an amorphous material and a crystalline metal layer. A portion of the crystalline metal layer is removed photolithographically and the amorphous material is etched to form a hole extending to the semiconductor substrate. The through hole is filled when a second amorphous material is deposited on the crystalline metal layer. A second hole is photolithographically prepared in the second amorphous material, partially aligned with the first hole and filled with a gate electrode material, and thereafter the second amorphous material, crystalline metal layer, and original amorphous material are removed, leaving a gate electrode having a leg with mutually offset portions.

Method of making field effect transistor

A gain coupled distributed feedback semiconductor laser device includes regions with a predetermined period in an active layer or a cladding layer on the active layer in such a manner that a perturbation in the distribution of charge carriers injected into the active layer is produced which results in a perturbation in gain coefficient without increasing internal loss. The structure produces single-longitudinal-mode oscillation.

Semiconductor distributed-feedback laser device

A mushroom-shaped gate electrode has a lower end in a recess in a semiconductor active layer on a semiconductor substrate. The gate electrode has an enlarged head. A metallic side wall is disposed on a portion of the leg of the gate electrode adjacent the head. Thus, the gate length of a semiconductor device, such as a field effect transistor, is reduced while the effective cross-sectional area of the gate electrode is increased whereby the noise characteristics of the semiconductor device are improved.

Method of making a mushroom-shaped gate electrode of semiconductor device

An AlGaAs/GaAs system light emitting device includes a GaAs substrate doped with a first conductivity type impurity, a first conductivity type Al.sub.y Ga.sub.1-y As first cladding layer, an Al.sub.x Ga.sub.1-x As (0 &lt;x&lt;y) active layer, and an Al.sub.y Ga.sub.1-y As second cladding layer having a second conductivity type opposite to the first conductivity type successively disposed on the substrate. The light emitting device includes an Al.sub.z Ga.sub.1-z As (z.gtoreq.0) buffer layer which is disposed between the GaAs substrate and the first cladding layer containing a dopant impurity in such a high concentration that the intensity of photoluminescent light generated due to the band-to-band transitions is reduced and has a smaller energy band gap than the energy of the light emitted from the light emitting device. Therefore, a long lifetime semiconductor light emitting device having no sub peak in the light emission spectrum can be easily produced with good yield.

Growing community of inventors

Itami, Japan

Tetsuya Yagi