Hitachi, Ltd.

Opnext Japan, Inc.

Akira Taike

Masahito Migita

Hiroshi Sato

Masatoshi Shiiki

Tomonobu Tsuchiya

Masahiro Aoki

Kazuhisa Uomi

Shinji Tsuji

Kazunori Shinoda

Tsukuru Ohtoshi

Masaaki Komori

Tsurugi Sudoh

Kazuhiro Ito

Kouji Nakahara

Yasunobu Matsuoka

Shigehisa Tanaka

Sumiko Fujisaki

Tomohiro Ohno

The prior art distributed feedback laser having an InGaAlAs active layer involves a problem that its laser characteristics are deteriorated at high temperature due to the high device resistance. According to the present invention, a ridge type laser is fabricated by: forming an InGaAlAs-MQW layeron a n-type InP substrate; growing a p-type InGaAlAs-GRIN-SCH layer, a p-type InAlAs electron stopping layerand a p-type grating layerin this order on the InGaAlAs-MQW layer; forming a grating; and regrowing a p-type InP cladding layerand a p-type InGaAs contact layer in this order. The concave depth of the grating is smaller than the thickness of the p-type grating layer

Distributed feedback semiconductor laser equipment employing a grating

An optical transmission device suitable for a high-speed and large-capacity optical transmission system. An optoelectronic waveguiding device including an optical waveguide layer and cladding layers each having a larger band gap than that of the optical waveguide are deposited above and beneath the optical waveguide layer formed on a semiconductor substrate. The waveguide and cladding layers comprise optical waveguides each having a MQW structure in a direction of a light propagation axis of the optical waveguide layer. Among these optical waveguides, there exists first and second optical waveguides, whose layer structures may be mutually different. The optoelectronic waveguiding device maybe characterized in that an optical waveguide made of a bulk crystal exists in a connection part between the MQW structure waveguides each having a different layer structure. The specific connected optoelectronic waveguiding device elements may include semiconductor lasers, modulators and/or amplifiers.

Optoelectronic waveguiding device and optical modules

Burying type avalanche photodiode and fabrication method thereof

An optical transmission device particularly adapted to a high-speed and large-capacity optical transmission system with a large optical output and excellent reflection resistance includes a waveguide-type optical element for emerging light and an optical transmission path that is to be optically coupled to the waveguide-type optical element. The waveguide-type optical element includes, at least in part thereof, a light-emitting portion having a gain-coupled diffraction grating and a mode-converting region integrated with the light-emitting portion.

Optical transmission device

A semiconductor light-emitting device containing as first and second semiconductor layers a semiconductor of Cd.sub.x Zn.sub.1-x S.sub.y Se.sub.1-y (0&lt;x.ltoreq.1, 0.ltoreq.y.ltoreq.1) and as an active layer a semiconductor of Cd.sub.x Zn.sub.1-x S.sub.y Se.sub.1-y (0.ltoreq.x.ltoreq.1, 0.ltoreq.y.ltoreq.1) formed between the first and second semiconductor layers, if necessary sandwiching the active layer with a pair of light guiding layers, can emit a blue laser light excellent in properties and high in reliability.

Semiconductor light-emitting device with cadmium zinc selenide layer

A semiconductor emitting device is provided which is capable of emitting a blue light and, which comprises a double hetero junction structure having first clad layer, an active layer and a second clad layer, successively formed on a semiconductor substrate. First and second electrodes are respectively formed on the first and second clad layers. ZnSSe thin films of low-resistivity are preferably used as the first and/or clad second layers, while a ZnSTe film can be used as the active layer.

Semiconductor emitting device

A semiconductor emitting device is provided which is capable of emitting a blue light. The device includes a first clad layer, an active layer and a second clad layer, successively formed on a semiconductor substrate. A nitrogen-doped p-type ZnSSe thin film of low-resistivity having a carrier concentration of not less than 1.times.10.sup.16 cm.sup.-3 and a resistivity of not more than 10 .OMEGA.-cm is used as the first clad layer or the second clad layer.

Strained-layer superlattices are formed on a substrate by alternately and epitaxially laminating a plurality of first compound semiconductor layers each of which is composed of a II-Vi compound semiconductor and second compound semiconductor layers each of which is composed of a II-VI or III-V compound semiconductor having a smaller lattice constant than the compound semiconductor of the first compound semiconductor layer. A first conduction type impurity diffusion region is formed in at least each layer surface of the first compound semiconductor layers, and a second conduction type region is so formed as to be adjacent to the first conduction type impurity diffusion region directly or through an undoped region. Electrodes are provided on the end side surfaces of the respective regions. The thus-obtained compound semiconductor light emitting device efficiently emits light in the visible region including green to blue wavelength region.

Growing community of inventors

Kokubunji, Japan

Akira Taike