US4246549A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magneto-optical phase-modulating devices
Assignee: BAE Systems PLC
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Filing: 1978-10-02
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Granted: 1981-01-20
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Expires: 1998-10-02
Abstract
Abstract The invention provides a magneto-optical phase-modulating device employing either the transverse Kerr magneto-optic effect or the Faraday magneto-optic effect and embodying a magneto-optic layer (1) of a ferromagnetic or ferrimagnetic garnet type material which gives rise to an improved performance over known devices. Examples of the garnet type material which may be employed are a bismuth doped garnet, praseodymium and a garnet type material of the group known as orthoferrite materials. The invention finds particular application in laser gyroscopes.
Inventors
- 👤 Walter S. Carter
- 👤 Richard B. Inwood
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 10:53
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/09; H; H01; H01S; H01S3/00; H01S3/05; H01S3/08; H01S3/081; H01S3/083
Claims Analysis
Total Claims: 39
Claim 1
Independent Claim
67 words
A device employing the transverse Kerr magneto-optic effect for phase modulating p-polarized light incident thereto comprising: a magneto-optic layer of bismuth doped garnet having the formula Bi 3-2y Ca 2y Y y Fe 5-y O 12 where preferably y 1; a reflective layer positioned adjacent to the magneto-optic layer such that the p-polarized light is first incident to the magneto-optic layer and therefrom to the reflective layer.
Claim 2
Independent Claim
67 words
A device employing the transverse Kerr magneto-optic effect for phase modulating p-polarized light incident thereto comprising: a magneto-optic layer of bismuth doped garnet having the formula Bi 3-2y Ca 2y Y y Fe 5-y O 12 where preferably y 1; a reflective layer positioned adjacent to the magneto-optic layer such that the p-polarized light is first incident to the magneto-optic layer and therefrom to the reflective layer.
Claim 3
Dependent Claim
28 words
A device according to claim 1 and further comprising a transparent substrate on which is disposed the magneto-optic layer with the reflective layer disposed on the magneto-optic layer.
Claim 4
Dependent Claim
27 words
A device according to claim 1, and further comprising a substrate on which is disposed the reflective layer, with the magneto-optic layer disposed on the reflective layer.
Claim 5
Independent Claim
27 words
A device according to claims 1, 2, or 3, wherein an anti-reflective layer is provided on the exterior surface to which the p-polarized light is first incident.
Claim 6
Dependent Claim
22 words
A device according to claim 4, wherein the anti-reflective layer is in the form of a single layer of a dielectric material.
Claim 7
Dependent Claim
26 words
A device according to claim 4, wherein the anti-reflective layer is of composite form and comprises a plurality of alternate layers of two different dielectric materials.
Claim 8
Dependent Claim
17 words
A device according to claim 6, wherein the two dielectric materials are magnesium fluoride and zinc sulfide.
Claim 9
Dependent Claim
9 words
A device according to claim 1, wherein y 1.
Claim 10
Independent Claim
25 words
A device according to claims 1, 2 or 3, wherein the reflective layer is in the form of a single layer of a dielectric material.
Claim 11
Independent Claim
29 words
A device according to claims 1, 2, or 3, wherein the reflective layer is of composite form and comprises a plurality of alternate layers of two different dielectric materials.
Claim 12
Dependent Claim
17 words
A device according to claim 10 wherein the two dielectric materials are magnesium fluoride and zinc sulfide.
Claim 13
Independent Claim
69 words
A device employing the transverse Kerr magneto-optic effect for phase modulating p-polarized light incident thereto comprising: a magneto-optic layer of praseodymium having the formula Pr x Y 3-x Fe 5-y Ga y O 12 where preferably x=0.62 and y=0.64; and a reflective layer positioned adjacent to the magneto-optic layer such that in operation the p-polarized light is first incident to the magneto-optic layer and therefrom to the reflective layer.
Claim 14
Independent Claim
69 words
A device employing the transverse Kerr magneto-optic effect for phase modulating p-polarized light incident thereto comprising: a magneto-optic layer of praseodymium having the formula Pr x Y 3-x Fe 5-y Ga y O 12 where preferably x=0.62 and y=0.64; and a reflective layer positioned adjacent to the magneto-optic layer such that in operation the p-polarized light is first incident to the magneto-optic layer and therefrom to the reflective layer.
Claim 15
Dependent Claim
10 words
A device according to claim 12, wherein x=0.62 and y=0.64.
Claim 16
Dependent Claim
27 words
A device according to claim 12 further comprising a transparent substrate on which is disposed the magneto-optic layer with the reflective layer disposed on the magneto-optic layer.
Claim 17
Dependent Claim
26 words
A device according to claim 12 further comprising a substrate on which is disposed the reflective layer, with the magneto-optic layer disposed on the reflective layer.
Claim 18
Independent Claim
27 words
A device according to claims 12, 14 or 15 wherein an anti-reflective layer is provided on the exterior surface to which the p-polarized light is first incident.
Claim 19
Dependent Claim
22 words
A device according to claim 16 wherein the anti-reflective layer is in the form of a single layer of a dielectric material.
Claim 20
Dependent Claim
26 words
A device according to claim 16 wherein the anti-reflective layer is of composite form and comprises a plurality of alternate layers of two different dielectric materials.
Claim 21
Dependent Claim
17 words
A device according to claim 18 wherein the two dielectric materials are magnesium fluoride and zinc sulfide.
Claim 22
Independent Claim
25 words
A device according to claims 12, 14 or 15 wherein the reflective layer is in the form of a single layer of a dielectric material.
Claim 23
Independent Claim
29 words
A device according to claims 12, 14 or 15 wherein the reflective layer is of composite form and comprises a plurality of alternate layers of two different dielectric materials.
Claim 24
Dependent Claim
17 words
A device according to claim 21 wherein the two dielectric materials are magnesium fluoride and zinc sulfide.
Claim 25
Dependent Claim
81 words
A laser gyroscope having laser cavity defined by a servoed mirror, an output mirror and a mirror embodying a magneto-optical phase modulating device wherein said phase modulating device comprises: a magneto-optic layer of bismuth doped garnet having the formula Bi 3-2y Ca 2y Y y Fe 5-y O 12 where preferably y 1; and a reflective layer positioned adjacent to the magneto-optic layer such that the p-polarized light is first incident to the magneto-optic layer and therefrom to the reflective layer.
Claim 26
Dependent Claim
81 words
A laser gyroscope having laser cavity defined by a servoed mirror, an output mirror and a mirror embodying a magneto-optical phase modulating device wherein said phase modulating device comprises: a magneto-optic layer of bismuth doped garnet having the formula Bi 3-2y Ca 2y Y y Fe 5-y O 12 where preferably y 1; and a reflective layer positioned adjacent to the magneto-optic layer such that the p-polarized light is first incident to the magneto-optic layer and therefrom to the reflective layer.
Claim 27
Dependent Claim
82 words
A laser gyroscope having laser cavity defined by a servoed mirror, an output mirror and a mirror embodying a magneto-optical phase modulating device wherein said phase modulating device comprises: a magneto-optic layer of praseodymium having the formula Pr x Y 3-x Fe 5-y Ga y O 12 where preferably x=0.62 and y=0.64; and a reflective layer positioned adjacent to the magneto-optic layer such that in operation the p-polarized light is first incident to the magneto-optic layer and therefrom to the reflective layer.
Claim 28
Dependent Claim
82 words
A laser gyroscope having laser cavity defined by a servoed mirror, an output mirror and a mirror embodying a magneto-optical phase modulating device wherein said phase modulating device comprises: a magneto-optic layer of praseodymium having the formula Pr x Y 3-x Fe 5-y Ga y O 12 where preferably x=0.62 and y=0.64; and a reflective layer positioned adjacent to the magneto-optic layer such that in operation the p-polarized light is first incident to the magneto-optic layer and therefrom to the reflective layer.
Claim 29
Independent Claim
61 words
A device employing the transverse Kerr magneto-optic effect for phase modulating p-polarized light incident thereto comprising: a magneto-optic layer of a material chosen from the group of materials known as orthoferrites; and a reflective layer positioned adjacent to the magneto-optic layer such that in operation the p-polarized light is first incident to the magneto-optic layer and therefrom to the reflective layer.
Claim 30
Independent Claim
61 words
A device employing the transverse Kerr magneto-optic effect for phase modulating p-polarized light incident thereto comprising: a magneto-optic layer of a material chosen from the group of materials known as orthoferrites; and a reflective layer positioned adjacent to the magneto-optic layer such that in operation the p-polarized light is first incident to the magneto-optic layer and therefrom to the reflective layer.
Claim 31
Dependent Claim
27 words
A device according to claim 25 further comprising a transparent substrate on which is disposed the magneto-optic layer with the reflective layer disposed on the magneto-optic layer.
Claim 32
Dependent Claim
26 words
A device according to claim 25 further comprising a substrate on which is disposed the reflective layer, with the magneto-optic layer disposed on the reflective layer.
Claim 33
Independent Claim
27 words
A device according to claims 25, 26 or 27 wherein an anti-reflective layer is provided on the exterior surface to which the p-polarized light is first incident.
Claim 34
Dependent Claim
22 words
A device according to claim 28 wherein the anti-reflective layer is in the form of a single layer of a dielectric material.
Claim 35
Dependent Claim
26 words
A device according to claim 28 wherein the anti-reflective layer is of composite form and comprises a plurality of alternate layers of two different dielectric materials.
Claim 36
Dependent Claim
17 words
A device according to claim 30 wherein the two dielectric materials are magnesium fluoride and zinc sulfide.
Claim 37
Independent Claim
25 words
A device according to claims 25, 26 or 27 wherein the reflective layer is in the form of a single layer of a dielectric material.
Claim 38
Independent Claim
29 words
A device according to claims 25, 26 or 27 wherein the reflective layer is of composite form and comprises a plurality of alternate layers of two different dielectric materials.
Claim 39
Dependent Claim
17 words
A device according to claim 33 wherein the two dielectric materials are magnesium fluoride and zinc sulfide.
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) | 1984-01-20 | 1984-07-21 | 1985-01-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-01-20 | 1988-07-21 | 1989-01-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-01-20 | 1992-07-21 | 1993-01-20 | $7700.00 | Window Closed / Lapsed |