US4746192A
Expired / Lapsed
US
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Diffraction grating and process for producing the same
Assignee: Hitachi Ltd
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Filing: 1986-06-18
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Granted: 1988-05-24
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Expires: 2006-06-18
Abstract
Abstract A diffraction grating having a delineated crystallographic diffraction plane which ensuess from a procedure of alternately growing two kinds single crystal layers on a single crystal substrate into multilayers, exposing a crystallographic plane other than the plane of growth in the above-mentioned single crystal layers of the two kinds of single crystal layers in the exposed crystallographic plane; and a process for producing a diffraction grating mentioned above.
Inventors
- 👤 Shigekazu Minagawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 18:30
CPC Classifications
G; G02; G02B; G02B5/00; G02B5/18; G02B5/1847; G02B5/1857; Y; Y10; Y10S; Y10S359/00; Y10S359/90
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
60 words
A diffraction grating comprising first crystal layers and second crystal layers alternately disposed epitaxially on a single crystal substrate, the end faces of the first crystal layers being formed on one flat crystallographic plane other than the plane of growth while the end faces of the second crystal layers being retracted from the end faces of the first crystal layers.
Claim 2
Dependent Claim
60 words
A diffraction grating comprising first crystal layers and second crystal layers alternately disposed epitaxially on a single crystal substrate, the end faces of the first crystal layers being formed on one flat crystallographic plane other than the plane of growth while the end faces of the second crystal layers being retracted from the end faces of the first crystal layers.
Claim 3
Dependent Claim
32 words
A diffraction grating as claimed in claim 1, wherein said first crystal layers are made of gallium arsenide, and said second crystal layers are made of aluminum gallium arsenide or aluminum arsenide.
Claim 4
Dependent Claim
35 words
A diffraction grating as claimed in claim 2, wherein said second crystal layers are made of aluminum gallium arsenide or aluminum arsenide represented by a general formula: Al x Ga 1-x As (provided that 0.3≦x≦1).
Claim 5
Dependent Claim
32 words
A diffraction grating as claimed in claim 1, wherein said first crystal layers are so formed as to gradually increase or decrease the thickness, thereof, whereby a chirped diffraction grating is formed.
Claim 6
Dependent Claim
15 words
A diffraction grating as claimed in claim 4, wherein plural said chirped gratings are incorporated.
Claim 7
Dependent Claim
61 words
A process for producing a diffraction grating comprising the steps of: (i) alternately growing epitaxially first crystal layers and second crystal layers on a single crystal substrate into multilayers; (ii) exposing a flat crystallographic plane other than the plane of growth in said first and second crystal layers; and (iii) selectively etching said second crystal layers on the exposed crystallographic plane.
Claim 8
Dependent Claim
61 words
A process for producing a diffraction grating comprising the steps of: (i) alternately growing epitaxially first crystal layers and second crystal layers on a single crystal substrate into multilayers; (ii) exposing a flat crystallographic plane other than the plane of growth in said first and second crystal layers; and (iii) selectively etching said second crystal layers on the exposed crystallographic plane.
Claim 9
Dependent Claim
36 words
A process for producing a diffraction grating as claimed in claim 6, wherein said first crystal layers are made of gallium arsenide, and said second crystal layers are made of aluminum gallium arsenide or aluminum arsenide.
Claim 10
Dependent Claim
39 words
A process for producing a diffraction grating as claimed in claim 7, wherein said second crystal layers are made of aluminum gallium arsenide or aluminum arsenide represented by a general formula: Al x Ga 1-x As (provided that 0.3≦x≦1).
Claim 11
Dependent Claim
21 words
A process for producing a diffraction grating as claimed in claim 6, wherein anisotropic etching is effected in said step (ii).
Claim 12
Dependent Claim
23 words
A process for producing a diffraction grating as claimed in claim 6, wherein a selective etching solution is used in said step (iii).
Claim 13
Dependent Claim
91 words
A process for producing a diffraction grating comprising the steps of: (i) alternately growing epitaxially first crystal layers and second crystal layers on a single crystal substrate into multilayers; (ii) exposing a flat crystallographic plane other than the plane of growth in said first and second crystal layers; (iii) selectively etching said second crystal layers on the exposed crystallographic plane; (iv) depositing a thick metal film on the end faces including the exposed crystallographic plane and the etched plane; and (v) dissolving away the crystals on which said metal is deposited.
Claim 14
Dependent Claim
91 words
A process for producing a diffraction grating comprising the steps of: (i) alternately growing epitaxially first crystal layers and second crystal layers on a single crystal substrate into multilayers; (ii) exposing a flat crystallographic plane other than the plane of growth in said first and second crystal layers; (iii) selectively etching said second crystal layers on the exposed crystallographic plane; (iv) depositing a thick metal film on the end faces including the exposed crystallographic plane and the etched plane; and (v) dissolving away the crystals on which said metal is deposited.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-05-24 | 1991-11-23 | 1992-05-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-05-24 | 1995-11-23 | 1996-05-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-05-24 | 1999-11-23 | 2000-05-24 | $7700.00 | Window Closed / Lapsed |