Patent EP0420749A2 successfully refreshed from Google Patents.
EP0420749A2
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EP
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Optical semiconductor device
Assignee: Fujitsu Ltd
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Filing: 1990-09-26
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Granted: —
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Expires: 2010-09-26
Abstract
Abstract The device is in the form of InP p-n diode having a multiple quantum well structure (6) between the p and n layers (8, 10), and consists of an InP layer and an In 1-x Ga x As well layer as an active layer. It can be made as an optical modulating diode in which the x-composition has e.g. a value of 0.44 which is made smaller than the x value 0.47 at which lattices are matched so as to cause compressive strain in the well layer, or as an optical bistable diode in which the x-composition has e.g. a value of 0.55 which is greater than 0.47, so as to cause tensile strain in the well layer.
Inventors
- 👤 Mitsuru Sugawara
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 17:27
CPC Classifications
B; B82; B82Y; B82Y20/00; G; G02; G02F; G02F1/00; G02F1/01; G02F1/015; G02F1/017; H; H10; H10F; H10F77/00; H10F77/10; H10F77/14; H10F77/146; G02F1/0155; G02F1/0157; G02F1/01708; G02F1/01766
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
85 words
An optical semiconductor device having a multi-quantum well (MQW) structure in which well layers and barrier layers made up of different kinds of semiconductor layers are alternately laminated, said optical semiconductor device comprising: a barrier layer having a definite lattice constant; and a well layer having a lattice constant different from the lattice constant of said barrier layer, wherein an optical absorption intensity, is increased, due to at least one exciton produced in said well layer because of lattice strain caused in said well layer.
Claim 2
Dependent Claim
85 words
An optical semiconductor device having a multi-quantum well (MQW) structure in which well layers and barrier layers made up of different kinds of semiconductor layers are alternately laminated, said optical semiconductor device comprising: a barrier layer having a definite lattice constant; and a well layer having a lattice constant different from the lattice constant of said barrier layer, wherein an optical absorption intensity, is increased, due to at least one exciton produced in said well layer because of lattice strain caused in said well layer.
Claim 3
Dependent Claim
74 words
An optical semiconductor device as claimed in claim 1, wherein said barrier layer is composed of any of indium phosphide (InP), indium aluminum arsenide (In 1-x Al x As) and indium gallium arsenide phosphide (In 1-x Ga x As 1-y P y ), and said well layer is composed of any of indium gallium arsenide (In 1-x Ga x As) and indium gallium arsenide phosphide (In 1-x Ga x As 1-y P y ).
Claim 4
Dependent Claim
25 words
An optical semiconductor device as claimed in claim 2, wherein the composition x of said well layer ranges from 0.35 to 0.60, most preferably 0.44.
Claim 5
Dependent Claim
38 words
An optical semiconductor device as claimed in one of claims 2 and 3, wherein the thickness of said well layer indium gallium arsenide (In 1-x Ga x As) is 5 to 15 nm, most preferably approximately 10 nm.
Claim 6
Dependent Claim
38 words
An optical semiconductor device as claimed in one of claims 2 and 3, wherein said optical semiconductor device is a modulator in which said MQW structure is interposed between a p-type InP layer and an n-type InP layer.
Claim 7
Dependent Claim
122 words
An optical semiconductor device having a multi-quantum well (MQW) structure in which well layers and barrier layers made up of different kinds of semiconductor layers are alternately laminated, said optical semiconductor device comprising: a barrier layer having a definite lattice constant; and a well layer having a lattice constant smaller than the lattice constant of said barrier layer, wherein the position of the optical absorption peak due to an exciton associated with an electron and a heavy hole produced in said well layer is caused to occur on the shorter wavelength side than the position of the optical absorption peak due to an exciton associated with an electron and a light hole because of tensile strain which occurs in said well layer.
Claim 8
Dependent Claim
122 words
An optical semiconductor device having a multi-quantum well (MQW) structure in which well layers and barrier layers made up of different kinds of semiconductor layers are alternately laminated, said optical semiconductor device comprising: a barrier layer having a definite lattice constant; and a well layer having a lattice constant smaller than the lattice constant of said barrier layer, wherein the position of the optical absorption peak due to an exciton associated with an electron and a heavy hole produced in said well layer is caused to occur on the shorter wavelength side than the position of the optical absorption peak due to an exciton associated with an electron and a light hole because of tensile strain which occurs in said well layer.
Claim 9
Dependent Claim
74 words
An optical semiconductor device as claimed in claim 6, wherein said barrier layer is composed of any of indium phosphide (InP), indium aluminum arsenide (In 1-x Al x As) and indium gallium arsenide phosphide (In 1-x Ga x As 1-y P y ), and said well layer is composed of any of indium gallium arsenide (In 1-x Ga x As) and indium gallium arsenide phosphide (In 1-x Ga x As 1-y P y ).
Claim 10
Dependent Claim
26 words
An optical semiconductor device as claimed in claim 7, wherein the composition x of said well layer ranges from 0.47 to 0.60, and is preferably 0.55.
Claim 11
Dependent Claim
39 words
An optical semiconductor device as claimed in one of claims 7 and 8, wherein the thickness of said well layer indium gallium arsenide (In 1-x Ga x As) is 5 to 15 nm, and is preferably about 10 nm.
Claim 12
Dependent Claim
38 words
An optical semiconductor device as claimed in one of claims 7 and 8, wherein said optical semiconductor device is a modulator in which said MQW structure is interposed between a p-type InP layer and an n-type InP layer.
References Cited (Backward Citations)
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