US3650601A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magneto-optic device having alternate layer film structure
Assignee: EIDP Inc
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Filing: 1970-11-19
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Granted: 1972-03-21
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Expires: 1990-11-19
Abstract
Abstract Kerr magneto-optic transducers having enhanced conversivity can be fabricated using a plurality of thin magnetic mirror layers spaced by dielectric layers having a thickness of approximately Mu /4 where lambda is the wavelength of the light employed for readout.
Inventors
- 👤 John David Bierlein
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 15:02
CPC Classifications
G; G11; G11B; G11B11/00; G11B11/10; G11B11/105; G11B11/10532; G11B11/10541; G11B11/10543; G11B11/10547; G02; G02F; G02F1/00; G02F1/01; G02F1/09
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
154 words
A magneto-optic device for converting a pattern of magnetic signals on a magnetic layer to an optical image by rotation of the plane of polarized light reflected from said layer consisting essentially of: a. an isotropic dielectric incident medium of refractive index N at the wavelength lambda of the incident light; b. a multilayer film structure of one face of said medium having layers in physical and optical contact composed of, in sequence, at least two assemblies of: i. a ferromagnetic layer, and ii. a dielectric layer the thickness of the ferromagnetic layer being such that when di is the thickness of the ith magnetic layer and ki is the imaginary part of the refractive index of said layer, each of said dielectric layer having a thickness and a refractive index calculated to optimize the coercivity of said magneto-optic device; and c. a nonmagnetic metallic reflecting layer opaque to light of wavelength lambda .
Claim 2
Dependent Claim
154 words
A magneto-optic device for converting a pattern of magnetic signals on a magnetic layer to an optical image by rotation of the plane of polarized light reflected from said layer consisting essentially of: a. an isotropic dielectric incident medium of refractive index N at the wavelength lambda of the incident light; b. a multilayer film structure of one face of said medium having layers in physical and optical contact composed of, in sequence, at least two assemblies of: i. a ferromagnetic layer, and ii. a dielectric layer the thickness of the ferromagnetic layer being such that when di is the thickness of the ith magnetic layer and ki is the imaginary part of the refractive index of said layer, each of said dielectric layer having a thickness and a refractive index calculated to optimize the coercivity of said magneto-optic device; and c. a nonmagnetic metallic reflecting layer opaque to light of wavelength lambda .
Claim 3
Dependent Claim
56 words
The device of claim 1 in which said incident medium is a prism having the said multilayer film structure deposited on one face thereof opposite an edge of the prism having an angle of 180*-2 Alpha , where Alpha is the angle of incidence of the incident light on said multilayer film from within said prism.
Claim 4
Dependent Claim
12 words
The device of claim 2 in which said ferromagnetic layer is iron.
Claim 5
Dependent Claim
12 words
The device of claim 2 in which said reflecting layer is silver.
References Cited (Backward Citations)
US3142720A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-03-21 | 1975-09-20 | 1976-03-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-03-21 | 1979-09-20 | 1980-03-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-03-21 | 1983-09-20 | 1984-03-21 | $7700.00 | Window Closed / Lapsed |