US4143939A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magneto optical deflector
Assignee: Thales SA
•
Filing: 1977-06-28
•
Granted: 1979-03-13
•
Expires: 1997-06-28
Abstract
Abstract The invention concerns the magneto-optical deflectors which enable an incident beam of radiant energy to be deflected in a variable manner under the control of a magnetic field. It consists in using a thin film of a magnetic material forming a diffraction grating, means for travelling the incident beam along the plane of this thin film, and means for magnetically controlling the step-width of the grating, thus controlling the angle of deflection given by this grating.
Inventors
- 👤 Bernard Desormiere
- 👤 Georges Hepner
- 👤 Jean-Paul Castera
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 09:33
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/09; G02F1/095; G02F1/29; G02F1/295; G02F1/2955
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
102 words
A magneto-optical deflector for deflecting an incident light beam having a first direction into at least one emerging beam having a deflected direction slightly variable about a fixed second direction, which comprises: a thin layer of homogeneous magnetic material having oppositely magnetized stripe domains, said domains extending along a third direction parallel to the layer; means for applying to said layer a magnetic field parallel to said third direction; the spacing of the domains being dependent upon the value of said field; and means for entering said incident beam into said layer, and means for extracting said emerging beam from the layer.
Claim 2
Dependent Claim
102 words
A magneto-optical deflector for deflecting an incident light beam having a first direction into at least one emerging beam having a deflected direction slightly variable about a fixed second direction, which comprises: a thin layer of homogeneous magnetic material having oppositely magnetized stripe domains, said domains extending along a third direction parallel to the layer; means for applying to said layer a magnetic field parallel to said third direction; the spacing of the domains being dependent upon the value of said field; and means for entering said incident beam into said layer, and means for extracting said emerging beam from the layer.
Claim 3
Dependent Claim
78 words
A deflector as claimed in claim 1, wherein said incident beam is a beam of parallel monochromatic light having a first polarization for initially propagating in said layer according to a first pure mode of guided propagation, and said layer is made with Gadolinium and Gallium substituted garnet of Yttrium and Iron; said emerging beam having a second polarization crossed with said first polarization and corresponding to a second pure mode of guided propagation induced by said layer.
Claim 4
Dependent Claim
24 words
A deflector as claimed in claim 2, wherein said entering means comprise a bi-refractive entry prism for selecting the polarization of said incident beam.
Claim 5
Dependent Claim
48 words
A deflector as claimed in claim 3, wherein the composition of said layer is substantially given by the formula Gd 0 .45 Y 2 .55 Fe 4 .2 Ga 0 .8 O 12 ; the layer being deposited onto a substrate made with a Gadolinium and Gallium garnet.
Claim 6
Dependent Claim
19 words
A deflector as claimed in claim 4, wherein the thickness of said layer is substantially equal to 4.4 μm.
Claim 7
Dependent Claim
23 words
A deflector as claimed in claim 5, wherein said incident beam is an infrared beam having a wavelength substantially equal to 1.15 μm.
Claim 8
Dependent Claim
35 words
A deflector as claimed in claim 6, wherein first and second directions are inclined relative to said third direction at angles substantially equal to 1.3°; said angles being measured in the atmosphere outside the layer.
Claim 9
Dependent Claim
48 words
A deflector as claimed in claim 3, wherein said extracting means comprise a bi-refractive exit prism for separating from said emerging beam a non deflected beam having said first directions and corresponding to a remainder part of the incident beam being propagated according to said first pure mode.
Claim 10
Dependent Claim
17 words
A deflector as claimed in claim 8, further comprising a screen for intercepting said non deflected beam.
Claim 11
Dependent Claim
19 words
A deflector as claimed in claim 7, wherein the incident beam propagates into said layer along substantially 1 cm.
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) | 1982-03-12 | 1982-09-11 | 1983-03-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-03-12 | 1986-09-11 | 1987-03-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-03-12 | 1990-09-11 | 1991-03-13 | $7700.00 | Window Closed / Lapsed |