Patent US3585614A successfully refreshed from Google Patents.
US3585614A
Expired / Lapsed
US
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Faraday effect readout of magnetic domains in magnetic materials exhibiting birefringence
Assignee: AT&T Inc
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Filing: 1969-05-23
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Granted: 1971-06-15
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Expires: 1989-05-23
Abstract
Abstract A plurality of layers of magnetic birefringent material exhibiting Faraday rotation changes the periodic effect of birefringence on that rotation, characteristic of a single layer of such material, into a continual enhancement of Faraday rotation if each of those layers is less than a critical thickness and if adjacent layers are oriented at about 90* with respect to one another. Optical readout of single wall domain propagation devices is improved by arranging at least a readout position accordingly.
Inventors
- 👤 William J Tabor
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 14:29
CPC Classifications
G; G11; G11C; G11C19/00; G11C19/02; G11C19/08; G11C19/0866; G02; G02F; G02F1/00; G02F1/01; G02F1/09
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
96 words
Apparatus comprising a plurality of layers of birefringent magnetic material which exhibits Faraday rotation, each of said layers having along an optical path a thickness T about equal to or less than (n+ 1/2 ) delta where delta is the thickness of each layer for 2 pi retardation of radiation of wavelength lambda and n is a whole number, adjacent ones of said layers having an orientation and a magnetization such that light directed along said optical path generates Faraday components in one of said layers which are additive to similarly generated components in adjacent layers.
Claim 2
Dependent Claim
96 words
Apparatus comprising a plurality of layers of birefringent magnetic material which exhibits Faraday rotation, each of said layers having along an optical path a thickness T about equal to or less than (n+ 1/2 ) delta where delta is the thickness of each layer for 2 pi retardation of radiation of wavelength lambda and n is a whole number, adjacent ones of said layers having an orientation and a magnetization such that light directed along said optical path generates Faraday components in one of said layers which are additive to similarly generated components in adjacent layers.
Claim 3
Dependent Claim
23 words
Apparatus in accordance with claim 1 wherein said adjacent layers are of opposite magnetization and have the axeS thereof aligned with one another.
Claim 4
Dependent Claim
22 words
Apparatus in accordance with claim 1 wherein each of said layers has a first magnetization and orientation and comprises a half-wave plate.
Claim 5
Dependent Claim
25 words
Apparatus in accordance with claim 1 wherein said layers are of like magnetization and have their axes oriented at angles with respect to one another.
Claim 6
Dependent Claim
14 words
Apparatus in accordance with claim 4 wherein each of said angles is about 90*.
Claim 7
Dependent Claim
15 words
Apparatus in accordance with claim 4 wherein said layers comprise crystalline particles in a binder.
Claim 8
Dependent Claim
22 words
Apparatus in accordance with claim 5 wherein at least one of said layers is capable of having single wall domains moved therein.
Claim 9
Dependent Claim
32 words
Apparatus in accordance with claim 7 in combination with a source of polarized light and means for detecting the passage of said light through said plurality of layers at an output position.
Claim 10
Dependent Claim
20 words
A combination in accordance with claim 8 also including means for selectively moving single wall domains to said output position.
Claim 11
Dependent Claim
108 words
Apparatus comprising a multilayered sheet of birefringent magnetic material which exhibits Faraday rotation and in which single wall domains can be moved, means for defining in said sheet a plurality of locations for single wall domains, means for moving single wall domains to selected ones of said positions, each of the layers of said sheet having a thickness T (n+ 1/2 ) delta where delta is the thickness of the sheet for 2 pi retardation of radiation of wavelength lambda transmitted therethrough and where n is a whole number, and means for directing at a selected one of said positions in said sheet radiation of wavelength lambda .
Claim 12
Dependent Claim
108 words
Apparatus comprising a multilayered sheet of birefringent magnetic material which exhibits Faraday rotation and in which single wall domains can be moved, means for defining in said sheet a plurality of locations for single wall domains, means for moving single wall domains to selected ones of said positions, each of the layers of said sheet having a thickness T (n+ 1/2 ) delta where delta is the thickness of the sheet for 2 pi retardation of radiation of wavelength lambda transmitted therethrough and where n is a whole number, and means for directing at a selected one of said positions in said sheet radiation of wavelength lambda .
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-06-14 | 1974-12-14 | 1975-06-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-06-14 | 1978-12-14 | 1979-06-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-06-14 | 1982-12-14 | 1983-06-15 | $7700.00 | Window Closed / Lapsed |