US4770504A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magneto-optical light switching element and method of manufacturing same
Assignee: US Philips Corp
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Filing: 1987-03-03
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Granted: 1988-09-13
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Expires: 2007-03-03
Abstract
Abstract A magneto-optical light switching element comprising islands which are formed from an epitaxial layer on the basis of bismuth-substituted rare earth metal iron garnet, which layer is provided on a magnetically unordered, optically transparent, (111)-oriented garnet substrate, integrated heating resistors being provided on the islands which are surrounded by a coil, the epitaxial layer being grown from a melt which contains lead oxide and boron oxide as a flux, the boron content of the melt used for growing the epitaxial layer being in the range from 12.7 to 25 at % (cation content) and the coil being constructed as an integrated coil.
Inventors
- 👤 Peter Hansen
- 👤 Claus-Peter Klages
- 👤 Klaus-Peter Schmidt
- 👤 Wolfgang F. M. Tolksdorf
- 👤 Klaus Witter
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 04:47
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/09
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
115 words
A magneto-optical switching element comprising: a magnetically unordered, optically transparent, (111)-oriented garnet substrate; a plurality of islands formed from an epitaxial layer on said substrate, said layer formed on the basis of bismuth-substituted rare earth metal iron garnet, grown from a melt which contains lead oxide and boron oxide as a flux, said boron content being in the range from 12.7 to 25 at. % (cation content); a plurality of heating resistors disposed on said plurality of islands; and an integrated coil formed on said substrate having turns which surround said islands, said integrated coil generating a magnetic flux which in combination with heat produced by said heating resistors, controls light passage through said islands.
Claim 2
Dependent Claim
115 words
A magneto-optical switching element comprising: a magnetically unordered, optically transparent, (111)-oriented garnet substrate; a plurality of islands formed from an epitaxial layer on said substrate, said layer formed on the basis of bismuth-substituted rare earth metal iron garnet, grown from a melt which contains lead oxide and boron oxide as a flux, said boron content being in the range from 12.7 to 25 at. % (cation content); a plurality of heating resistors disposed on said plurality of islands; and an integrated coil formed on said substrate having turns which surround said islands, said integrated coil generating a magnetic flux which in combination with heat produced by said heating resistors, controls light passage through said islands.
Claim 3
Dependent Claim
39 words
A magneto-optical light switching element as claimed in claim 18 wherein the epitaxial layer consists of bismuth-substituted rare earth metal (SE) iron garnet in accordance with the general formula (SE, Bi) 3 (Fe, Ga, Al) 5 O 12 .
Claim 4
Dependent Claim
41 words
A magneto-optical light switching element as claimed in claim 2, wherein the composition of the epitaxial layer is in accordance with the formula Gd 2 ,01 Bi 0 .99 Fe 4 ,43 Ga 0 .19 Al 0 ,38 O 12 .
Claim 5
Dependent Claim
41 words
A magneto-optical light switching element as claimed in claim 3, wherein the cation content of the melt used for growing the epitaxial layer has the following values: Pb 35.11; Bi 31.38; B 16.55; Fe 13.88; Gd 0.83; Ga 0.53; Al 1.72.
Claim 6
Dependent Claim
20 words
A magneto-optical light switching element as claimed in claim 1 wherein the substrate consists of rare earth metal gallium garnet.
Claim 7
Dependent Claim
36 words
A magneto-optical light switching element as claimed in claim 5, wherein the substrate consists of calcium magnesium zirconium-substituted gadolinium gallium garnet (GGCMZ) of the general formula (Gd, Ca) 3 (Ga, Mg, Zr) 5 O 12 .
Claim 8
Dependent Claim
32 words
A magneto-optical light switching element as claimed in claim 5, wherein the substrate consists of calcium magnesium zirconium-substituted neodymium gallium garnet of the general formula (Nd,Ca) 3 (Ga,Mg,Zr) 5 O 12 .
Claim 9
Independent Claim
87 words
A method for manufacturing a magneto-optical light switching element comprising: forming a melt on the basis of bismuth-substituted rare earth metal iron garnet having a boron content in the range from 12.7 to 25 at. % (cation content); depositing an epitaxial layer of said melt on a magnetically unordered, optically transparent, (111)-oriented garnet substrate; forming a plurality of islands from said epitaxial layer using a photolithographic process; forming an integrated heating resistor on each island; and, forming an integrated coil which surrounds said islands on said substrate.
Claim 10
Independent Claim
87 words
A method for manufacturing a magneto-optical light switching element comprising: forming a melt on the basis of bismuth-substituted rare earth metal iron garnet having a boron content in the range from 12.7 to 25 at. % (cation content); depositing an epitaxial layer of said melt on a magnetically unordered, optically transparent, (111)-oriented garnet substrate; forming a plurality of islands from said epitaxial layer using a photolithographic process; forming an integrated heating resistor on each island; and, forming an integrated coil which surrounds said islands on said substrate.
Claim 11
Dependent Claim
19 words
A method as claimed in claim 8 wherein a rare earth metal gallium garnet is used as a substrate.
Claim 12
Dependent Claim
31 words
A method as claimed in claim 9, wherein a calcium magnesium zirconium-substituted gadolineum gallium garnet (GGCMZ) of the general formula (Gd,Ca) 3 (Ga,Mg,Zr) 5 O 12 is used as a substrate.
Claim 13
Dependent Claim
29 words
A method as claimed in claim 9, wherein a calcium magnesium zirconium-substituted neodymium gallium garnet of the general formula (Nd,Ca) 3 (Ga,Mg,Zr) 5 O 12 is used a substrate.
Claim 14
Dependent Claim
36 words
A method as claimed in claim 8, wherein an epitaxial layer of bismuthsubstituted rare earth metal (SE) iron garnet in accordance with the general formula (SE,Bi) 3 (Fe,Ga,Al) 5 O 12 is deposited on the substrate.
Claim 15
Dependent Claim
41 words
A method as claimed in claim 12, wherein an epitaxial layer having a composition in accordance with the formula Gd 2 ,01 Bi 0 ,99 Fe 4 ,43 Ga 0 ,19 Al 0 ,38 O 12 is deposited on the substrate.
Claim 16
Dependent Claim
40 words
A method as claimed in claim 13, in that for growing the epitaxial layer a melt is used having the following cation content in at %: Pb 35.11; Bi 31.38; B 16.55; Fe 13.88; Gd 0.83; Ga 0.53; Al 1.72.
Claim 17
Dependent Claim
24 words
A method as claimed in claim 8 wherein the deposited epitaxial layer has a layer thickness in the range from 1 to 10 μm.
Claim 18
Dependent Claim
23 words
A method as claimed in claim 8 wherein islands having a border length up to 500 μm are formed from the epitaxial layer.
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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) | 1991-09-13 | 1992-03-14 | 1992-09-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-09-13 | 1996-03-14 | 1996-09-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-09-13 | 2000-03-14 | 2000-09-13 | $7700.00 | Window Closed / Lapsed |