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US 6,075,801 AGranted
Semiconductor laser with wide side of tapered light gain region
AssigneeNEC Corporation
InventorsTakemasa Tamanuki, Hiroyuki Yamazaki
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AssigneeNEC Corporation
InventorsTakemasa Tamanuki, Hiroyuki Yamazaki
Estimating the term…
The semiconductor laser disclosed includes a first conductivity type buffer layer, an active layer and a second conductivity type cladding layer which are sequentially positioned on a first conductivity type semiconductor substrate. The active layer has a laser gain region to which an electric current is injected. The laser gain region having a width varying linearly along a resonating direction is disposed between a high reflection film provided on a facet of a wide side of the laser gain region of the active layer and a low reflection film provided on a facet of a narrow side of the laser gain region of the active layer. The facet of the narrow side is for outputting oscillation beams of a high order mode. This provides a high electrical-to-optical conversion efficiency, and enables the outputting of a large output from a narrow light emission region.
A semiconductor laser comprising a first conductivity type buffer layer and an active layer, said active layer being formed of one of two structures, one of said two structures being a multi-quantum well structure and the other of said two structures sandwiched by SCH layers being a multi-quantum well structure and a second conductivity type cladding layer, said active layer and said second conductivity type cladding layer being sequentially positioned on a first conductivity type semiconductor substrate, at least said active layer and said second conductivity type cladding layer being in a tapered ridge shape such that a width of said active layer is defined by said ridge shape, said width of said active layer varying linearly along a resonating direction, said tapered ridge shape defining a laser gain region comprising:
A composite semiconductor laser comprising a plurality of lasers, stacked one upon another, each having a first conductivity type buffer layer and an active layer, said active layer being formed of one of two structures, one of said two structures being a multi-quantum well structure and the other of said two structures sandwiched by SCH layers being a multi-quantum well structure and a second conductivity type cladding layer which are sequentially formed on a first conductivity type semiconductor substrate, at least said active layer and said second conductivity type cladding layer being in a tapered ridge shape such that a width of said active layer is defined by said ridge shape, said active layer having a laser gain region whose width varies linearly along a resonating direction, said laser gain region comprising:
Dependencies are inferred from the claim text.