Patent US4818722A successfully refreshed from Google Patents.
US4818722A
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Method for generating a strip waveguide
Assignee: Siemens AG
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Filing: 1987-05-26
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Granted: 1989-04-04
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Expires: 2007-05-26
Abstract
Abstract A method for generating a strip laser in a buried hetero-structure composed of layers, wherein a raised strip is etched out of the layer structure and the strip is laterally etched with an erosion melt. The lateral edges of the laser active layer are protected by leaving them covered with a portion of the layer dissolved out by the erosion melt. The deposits thus remaining are used to initiate the generation of an epitaxial layer which extends laterally from the laser-active layer.
Inventors
- 👤 Jochen Heinen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 12:24
CPC Classifications
G; G02; G02B; G02B6/00; G02B6/10; G02B6/12; G02B6/13; G02B6/136; H; H01; H01S; H01S5/00; H01S5/20; H01S5/22; H01S5/227; H01S5/2275; Y; Y10; Y10S; Y10S148/00; Y10S148/029; Y10S148/05; Y10S148/065; Y10S148/066; Y10S148/072; Y10S148/108; Y10S438/00; Y10S438/955
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
126 words
A method for generating a strip waveguide which comprises: providing an epitaxial hetero-layer structure composed of a laser-active layer located between two semiconductor layers, the width of said laser-active layer being greater than the width of the final laser-active layer, forming a raised strip (1) from the epitaxial hetero-layer structure, said strip being laterally etched with an erosion melt and the lateral surface (21, 22) of the laser-active layer (2) of the htero structure functioning as a waveguide region of the strip (1) is etched away laterally more than the two semiconductor layers and is left covered by one of the erosion melt or a part (5) of said layer dissolved by said melt, and growing an epitaxial layer laterally outwardly from said erosion melt deposits.
Claim 2
Independent Claim
126 words
A method for generating a strip waveguide which comprises: providing an epitaxial hetero-layer structure composed of a laser-active layer located between two semiconductor layers, the width of said laser-active layer being greater than the width of the final laser-active layer, forming a raised strip (1) from the epitaxial hetero-layer structure, said strip being laterally etched with an erosion melt and the lateral surface (21, 22) of the laser-active layer (2) of the htero structure functioning as a waveguide region of the strip (1) is etched away laterally more than the two semiconductor layers and is left covered by one of the erosion melt or a part (5) of said layer dissolved by said melt, and growing an epitaxial layer laterally outwardly from said erosion melt deposits.
Claim 3
Dependent Claim
37 words
A method according to claim 1 which includes the steps of removing said erosion melt after said etching except for said erosion melt deposits, and applying a growth melt to said deposits to gene-rate said epitaxial layer.
Claim 4
Dependent Claim
21 words
A method according to claim 1 wherein said erosion melt itself is used to generate said epitaxial layer from said deposits.
Claim 5
Dependent Claim
22 words
A method according to claim 1 wherein said laser-active layer is composed of indium-gallium-arsenic-phosphorus and said semiconductor layers are composed of indium-phosphorus.
Claim 6
Dependent Claim
20 words
A method according to claim 4 wherein said erosion melt is a less than saturated melt of phosphorus in indium.
Claim 7
Dependent Claim
16 words
A method according to claim 5 wherein the processing temperature is lowered during the etching process.
Claim 8
Dependent Claim
19 words
A method according to claim 4 wherein said erosion melt is a substantially saturated melt of phosphorus in indium.
Claim 9
Dependent Claim
15 words
A method according to claim 7 wherein said temperature is raised during the etching process.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-04-03 | 1992-10-03 | 1993-04-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-04-03 | 1996-10-03 | 1997-04-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-04-03 | 2000-10-03 | 2001-04-04 | $7700.00 | Window Closed / Lapsed |