Kabushiki Kaisha Toshiba

Hideo Shiozawa

Masayuki Ishikawa

Hajime Okuda

Kazuhiko Itaya

Genichi Hatakoshi

Yukio Watanabe

Yasuo Ohba

Yoshihiro Kokubun

Akira Tanaka

Mariko Suzuki

Yutaka Uematsu

Shigeya Naritsuka

Koichi Gen-Ei

Minoru Watanabe

Akihiro Kojima

Hideto Sugawara

Kazuhito Higuchi

Susumu Obata

Yukie Nishikawa

Hirokazu Tanaka

Toshiyuki Terada

Kazushige Mori

Akio Makuta

Koichi Gen-ei

Ichiro Uchizaki

Yoshiyuki Itoh

Osamu Horiuchi

A semiconductor light emitting device includes a light emitting unit, a first and second conductive pillar, a sealing unit, a translucent layer, and a wavelength conversion layer. The light emitting unit includes a first and second semiconductor layer and a light emitting layer. The first semiconductor layer has a first and second major surface. The first major surface has a first and second portion. The second major surface is opposed the first major surface and has a third and fourth portion. The light emitting layer is provided on the first portion. The second semiconductor layer is provided on the light emitting layer. The first conductive pillar is provided on the second portion. The second conductive pillar is provided on the second semiconductor layer. The translucent layer is provided on the fourth portion. The wavelength conversion layer is provided on the third portion and on the translucent layer.

Semiconductor light emitting device

The present invention provides a semiconductor laser element, a method of fabrication thereof, and a multi-wavelength monolithic semiconductor laser device that achieve self-sustained pulsation up to a high output level and achieve self-sustained pulsation over a wide output range. A semiconductor laser element that exhibits self-sustained pulsation in a predetermined output region, said semiconductor laser element comprising: a substrate; a first conductive type clad layer formed on said substrate; an active layer formed on said first conductive type clad layer for emitting light by current injection; a second conductive type first clad layer formed on said active layer; and a stripe-shaped second conductive type second clad layer formed on said second conductive type first clad layer in a first direction, in such a manner that the cross-sectional surface of said stripe-shaped second conductive type second clad layer in a direction perpendicular to said first direction has a shape having an upper edge and a lower edge that face each other and side edges that connect between said upper edge and said lower edge, where the minimum width thereof is at least 70% but no more than 100% of the maximum width.

Semiconductor laser element, method of fabrication thereof, and multi-wavelength monolithic semiconductor laser device

A semiconductor laser device comprises: a cladding layer of a first conductivity type; an active layer provided on the cladding layer; and a cladding layer of a second conductivity type provided on the active layer. At least a part of the cladding layer of the second conductivity type has a ridge stripe. The ridge stripe includes: an upper part having substantially vertical sidewalls; and a lower portion having sidewalls inclined so that the stripe becomes wider toward the active layer.

Semiconductor laser device and its manufacturing method

A semiconductor laser array including a plurality of index-guided semiconductor lasers different in oscillation wavelength is made by collectively controlling their double transverse modes and collectively processing them to form their current-blocking structures and buried layers. Thus, a semiconductor laser having a flat element surface and excellent in heat radiation can be made in a reduced number of manufacturing steps. When the laser array of this multi-wavelength type and a detector PD are mounted with a predetermined positional relationship, return light from an optical disk can be converted into a single point to enable detection thereof at PD on one chip. Therefore, an optical disk driving apparatus remarkably reduced in size and weight and having a high reliability can be realized.

Semiconductor laser array and its manufacturing method, optical integrated unit and optical pickup

This is a double wavelength semiconductor laser unit having a first laser emitting a light of a first wavelength and a second laser emitting a light of a second wavelength different from the first wavelength. The first and second lasers are merged on a substrate. The first laser has a bulk active layer whose film thickness is 0.01 &mgr;m or more and 0.1 &mgr;m or less. And the second laser has an MQW active layer constituted by stacked structure composed of a quantum well layer and a barrier layer. By employing the bulk active layer for the first laser, it is possible to reduce the band gap discontinuity induced at a boundary between a cladding layer and the bulk active layer, and then decreases an operational voltage, and further improve the reliability of the first laser.

Monolithic multi-wavelength semiconductor laser unit

An InGaAlP NAM structure laser is formed with a double-heterostructure section disposed on an n-type GaAs substrate. The double-heterostructure section includes a first cladding layer of n-type InGaAlP, a non-doped InGaP active layer, and a second cladding layer of p-type InGaAlP. An n-type GaAs current-blocking layer having a stripe opening and a p-type GaAs contact layer are sequentially formed on the second cladding layer by MOCVD crystal growth. A low-energy band gap region is defined in a central region of the active layer located immediately below the stripe opening. A high-energy band gap region is defined in a peripheral region of the active layer corresponding to a light output end portion of the laser and located immediately below the current-blocking layer. Therefore, self absorption of an oscillated laser beam at the output end portion can be reduced or prevented.

Manufacturing method of semiconductor laser with non-absorbing mirror

In a semiconductor laser device, for emitting a laser beam having a wavelength .lambda., an n-type In.sub.0.5 (Ga.sub.1-x Al.sub.x)P first cladding layer is formed on an n-type GaAs substrate. An undoped InGaP active layer is formed on the first cladding layer and a p-type In.sub.0.5 (Ga.sub.1-x Al.sub.x).sub.0.5 P cladding layer is formed on the active layer. A p-type InGaP cap layer is formed on the second cladding layer and an n-type GaAs current restricting layer is formed on the second cladding layer. The aluminum composition ratio x of the cladding layer is 0.7. The active layer has a thickness of 0.06 .mu.m and the cladding layers have the same thickness H of 0.85 .mu.m. The active layer and the cladding layers have refractive indices n.sub.a and n.sub.c which satisfies the following inequalities:

Semiconductor laser device

A semiconductor laser device using double heterostructure comprised of In.sub.x Ga.sub.y Al.sub.1-x-y P (0.ltoreq.x.ltoreq.1, 0.ltoreq.y.ltoreq.1), capable of preventing the leakage of the carriers and thereby reducing the threshold current, being operative with small threshold current density and at high temperature, and having a long lifetime. The device may include a double heterostructure formed on the GaAs substrate, comprised of In.sub.x Ga.sub.y Al.sub.1-x-y P (0.ltoreq.x.ltoreq.1, 0.ltoreq.y.ltoreq.1) including an active layer, the active layer having an impurity concentration not greater than 5.times.10.sup.16 cm.sup.-3. The device may include a double heterostructure formed on the GaAs substrate, comprised of InGaP active layer and p-type In.sub.q (Ga.sub.1-z Al.sub.z).sub.q P (0.ltoreq.q.ltoreq.1, 0.ltoreq.z.ltoreq.1) cladding layer with a value of z between 0.65 and 0.75. The device may include a double heterostructure formed on the GaAs substrate, comprised of In.sub.x Ga.sub.y Al.sub.1-x-y P (0.ltoreq.x.ltoreq.1, 0.ltoreq.y.ltoreq.1) including an n-type cladding layer and an p-type cladding layer, one of the n-type cladding layer and the p-type cladding layer being Si-doped. A method of manufacturing the device is also disclosed.

Semiconductor laser device which has a double-hetero structure having an

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Kanagawa, Japan

Hideo Shiozawa