Omron Tateisi Electronics Co.

Hiroshi Imamoto

Koichi Imanaka

A semiconductor laser having an internal current restriction includes a (100) face-oriented p-type GaAs substrate treated to have a groove or difference in level having an (n11) A face (n=1-5) as an inclined surface. An AlGaAs:Si layer, an AlGaAs:Be cladding layer, an AlGaAs active layer, and an AlGaAs:Sn cladding layer are grown on the substrate in the order mentioned. Since the Si acts as an n-type material on the (100) face and as a p-type material on the (n11) face, the AlGaAs:Si layer becomes a p-type layer solely in the groove, and it is in this portion that a current path is formed. The laser can be fabricated by molecular-beam epitaxy applied in a single step.

A stripe-shaped heterojunction laser with unique current confinement

In a laser having a separately confined heterostructure (SCH), a barrier layer is constituted with a superlattice of AlGaAs/GaAs each comprising two to five molecular layers such that the leakage of injection carriers is decreased, that a steep heterojunction plane is attained, and an active layer of a high quality is obtained, which leads to expectations for improvement of the temperature characteristic and the threshold current.

Semiconductor quantum well laser

A semiconductor laser having an internal current restriction includes a (100) face-oriented p-type GaAs substrate treated to have a groove or difference in level having an (n11) A face (n=1-5) as an inclined surface. An AlGaAs: Si layer, an AlGaAs:Be cladding layer, an AlGaAs active layer, and an AlGaAs:Sn cladding layer are grown on the substrate in the order mentioned. Since the Si acts as an n-type material on the (100) face and as a p-type material on the (n11) face, the AlGaAs:Si layer becomes a p-type layer solely in the groove, and it is in this portion that a current path is formed. The laser can be fabricated by molecular-beam epitaxy applied in a single step.

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Takatsuki, Japan

Hiroshi Imamoto