Nec Corporation

Nec Compound Semiconductor Devices, Ltd.

Hitoshi Hotta

Kenichi Kobayashi

Ryuji Kobayashi

Hiroyuki Sawano

Takahiro Arakida

Atsushi Shono

A semiconductor laser device includes an active layer and first and second current blocking layers having aligned stripe openings for injecting operating current into the active layer in a current injection area. The second current blocking layer has another opening, through which the first current blocking layer contacts an external cladding layer, in the vicinity of the emission facet of the laser cavity to form a current non-injection area. The first current blocking layer and the external cladding layer have a substantially equal refractive index.

Semiconductor laser device having a current non-injection area

A semiconductor laser device includes an inner lower clad layer formed on a semiconductor layer, an active layer formed on the inner lower clad layer, an inner upper clad layer formed the active layer, a blocking layer formed on the inner upper clad layer to block current, wherein the blocking layer having a concave portion, and an outer upper clad layer formed to cover the blocking layer. Carriers are injected to the active layer through the outer upper clad layer and the concave portion of the blocking layer.

Semiconductor laser device capable of preventing degradation of characteristics

A p-type saturable light absorbing layer is provided between p-type AlGaInP clad layers. Oxygen is doped in the p-type saturable light absorbing layer to generate non-luminescent recombination center, thereby consuming minority carrier. By this, minority carrier life of the p-type saturable light absorbing layer is lowered without saturation. Therefore, saturable light absorbing amount necessary for self-pulsation can be reduced to achieve a semiconductor laser with low threshold value, low drive current and high reliability.

Semiconductor laser

Disclosed herein is a selective metalorganic vapor phase growth method of a group III-V compound semiconductor containing at least Al and In, in which a ratio of an HCl gas supply amount to a supply amount of a group III metalorganic material (�HCl supply amount!/�group III supply amount!) is set in a range of 0.01-0.3. Hence, a polycrystal density is decreased to ensure a selectivity, and a grown crystal composition can be controlled so as not to be excessive in the Al composition so that composition control can be done easily.

Selective crystal growth method of compound semiconductor

A semiconductor laser having improved reliability. The laser contains an AlGaInP first cladding layer of a first conductivity type, an AlGaInP second cladding layer of a second conductivity type that forms a mesa stripe, an active layer made of an undoped GaInP layer, an undoped AlGaInP layer, or a quantum well layer of an undoped GaInP sublayer and an undoped AlGaInP sublayer. The laser further contains a burying layer made of an Al.sub.x In.sub.1-x P or (Al.sub.y Ga.sub.1-y).sub.x In.sub.1-x P layer, which is placed at both sides of the mesa stripe to bury the stripe. The burying layer is larger in energy band gap than the active layer and smaller in refractive index than the second cladding layer. The burying layer has first regions that are contacted with and extend along respective side faces of the mesa stripe. An Al composition x of the first regions is set so that the first regions are lattice-matched to GaAs. The burying layer has second regions that are joined with respective bottom ends of the first regions and extend along the active layer. An Al composition x of the second regions is set so that the second regions are lattice-matched or are not lattice-matched to GaAs.

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Tokyo, Japan

Hitoshi Hotta