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US 6,856,631 B1Granted
Semiconductor device with saturable absorbing layer
AssigneeRicoh Company, Ltd.
InventorTakashi Takahashi
Life of this patent
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Abstract
A self-pulsating semiconductor laser device includes a semiconductor substrate of the first conductivity type, a first cladding layer of the first conductivity type formed on the substrate and an active layer formed on the first cladding layer. A second cladding layer of a second conductivity type is formed on the active layer. A saturable absorbing layer is formed on at least portions of at least one of the first cladding layer and the second cladding layer. The saturable absorbing layer has a band gap energy either approximately the same as, or slightly smaller than, the active layer.
Claims15
A semiconductor device comprising:
- a semiconductor substrate of a first conductivity type;
- a first cladding layer of said first conductivity type formed on said semiconductor substrate;
- an active layer formed on said first cladding layer;
- a second cladding layer of a second conductivity type formed on said active layer;
- and
- a saturable absorbing layer formed on at least portions of at least one of said first cladding layer and said second cladding layer;
- wherein said saturable absorbing layer is formed to have a band gap energy either approximately the same as, or slightly smaller than, said active layer, and also to be doped with nitrogen (N) in an amount sufficient to form a localized level;
- wherein said saturable absorbing layer includes a III-V alloy material;
- and
- wherein said saturable absorbing layer comprises at least one of As and P.
7 more elements
A semiconductor device a comprising
- a semiconductor substrate of a first conductivity type;
- a first cladding layer of said first conductivity type formed on said semiconductor substrate;
- an active layer formed on said first cladding layer;
- a second cladding layer of a second conductivity type formed on said active layer;
- and
- a saturable absorbing layer formed on at least portions of at least one of said first cladding layer and said second cladding layer;
- wherein said saturable absorbing layer is formed to have a band gap energy either approximately the same as, or slightly smaller than, said active layer, and also to be doped with nitrogen (N) in an amount sufficient to form a localized level;
- wherein said saturable absorbing layer includes a III-V alloy material;
- and
- wherein said saturable absorbing layer comprises an AlGaInNP alloy material.
7 more elements
A semiconductor device comprising:
- a semiconductor substrate of a first conductivity type;
- a first cladding layer of said first conductivity type formed an said semiconductor substrate;
- an active layer formed on said first cladding layer;
- a second cladding layer of a second conductivity type formed on said active layer;
- and
- a saturable absorbing layer formed on at least portions of at least one of said first cladding layer and said second cladding layer;
- wherein said saturable absorbing layer is a mixed crystal of nitrogen (N) with another group-V element and is formed to have a band gap energy either approximately the same as, or slightly smaller than, said active layer.
4 more elements
A semiconductor device comprising:
- a semiconductor substrate of a first conductivity type;
- a first cladding layer of said first conductivity type formed on said semiconductor substrate;
- an active layer formed on said first cladding layer;
- a second cladding layer of a second conductivity type formed on said active layer;
- and
- a saturable absorbing layer formed on at least portions of at least one of said first cladding layer and said second cladding layer;
- wherein said saturable absorbing layer is formed to have a band gap energy either approximately the same as, or slightly smaller than, said active layer, and also to be doped with nitrogen (N) in an amount sufficient to form a localized level;
- and
- said saturable absorbing layer comprises at least one of As and P.
6 more elements
A semiconductor device comprising:
- a semiconductor substrate of a first conductivity type;
- a first cladding layer of said first conductivity type formed on said semiconductor substrate;
- an active layer formed on said first cladding layer;
- a second cladding layer of a second conductivity type formed on said active layer, and
- a saturable absorbing layer formed on at least portions of at least one of said first cladding layer and said second cladding layer;
- wherein said saturable absorbing layer is a mixed crystal of nitrogen (N) with another group-V element, and a band gap of said mixed crystal of nitrogen (N) with another group-V element is reduced by adding nitrogen;
- and
- said saturable absorbing layer is formed to have a band gap energy either approximately the same as, or slightly smaller than, said active layer.
5 more elements
Dependencies are inferred from the claim text.