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US3811941A
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Article for processing electromagnetic wave energy
Assignee: Massachusetts Institute of Technology
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Filing: 1971-08-23
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Granted: 1974-05-21
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Expires: 1991-08-23
Abstract
Abstract A device for processing electromagnetic wave energy by converting the wave energy to spin waves and/or elastic waves, the present disclosure being particularly directed to the concept of providing a device made up of a single-crystal material which contains non-uniform material parameters to give graded values of material saturation 4 pi Ms. The material discussed in greatest detail is YIG and the non-uniform material parameters are furnished by doping the YIG with gallium. The graded material parameters in combination with an external magnetic bias field H result in an internal magnetic bias field H. The electromagnetic energy as it enters the material is acted upon in a manner that is influenced greatly by the contour of H. The contour of H in the present disclosure, in turn, is predetermined to present gradations in H which will allow the conversion mentioned and which allow predetermination of the wavenumber k of the magnons and/or phonons thereby formed. Furthermore, the place or space within the crystal at which conversion occurs can be somewhat determined by the profile of H thereby provided.
Inventors
- 👤 F Morgenthaler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 20:42
CPC Classifications
H; H01; H01F; H01F10/00; H01F10/08; H01F10/10; H01F10/18; H01F10/20; H01F10/24; H01F10/245; C; C04; C04B; C04B35/00; C04B35/01; C04B35/26; C04B35/2675; H01P; H01P1/00; H01P1/20; H01P1/215; H03; H03F; H03F13/00; H03H; H03H9/00; H03H9/30; H03H9/38
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
179 words
An article for processing electromagnetic wave energy, that comprises, a magnetic material adapted to receive the electromagnetic energy, the material being one that will support propagating spin wave energy, the material being one in which the electromagnetic wave energy can be converted to propagating spin wave energy and in which the direction of the group velocity of the propagating spin wave can be varied by varying at least one of the magnitude and direction of a magnetic bias field within the material, the material being further adapted to receive an applied magnetic field which in combination with the magnetic characteristics of the material provides the internal magnetic bias field needed to effect spatial conversion from electromagnetic power to propagating spin waves, the spin waves being carried in the electromagnetic channel, the quantum mechanical exchange channel or a combination thereof, the material being doped to provide a predetermined grading of said magnetic characteristics thereby to provide a predetermined profile of internal magnetic bias field, said magnetic material comprising a plurality of regions, the material parameters varying from region to region.
Claim 2
Dependent Claim
70 words
An article as claimed in claim 2 and in which the regions are a plurality of layers adjacently disposed along the path of travel of the spin wave power, said conversion being effected by passing the wave energy successively from one to the other of the layers thereby to subject the wave energy to a plurality of successive discontinuities at the interfaces of said layers to provide abrupt spatial conversion.
Claim 3
Dependent Claim
54 words
An article as claimed in claim 2 and in which regions are transversely disposed within the material, the material being adapted to receive an applied magnetic field, the effect of which in combination with the material parameters being to provide a plurality of different-valued environmental parameters to the wave energy from region to region.
Claim 4
Dependent Claim
212 words
An article for processing electromagnetic wave energy, that comprises, a magnetic material adapted to receive the electromagnetic energy, the material being one that will support propagating spin wave energy, the material being one in which the electromagnetic wave energy can be converted to propagating spin wave energy and in which the dirEction of the group velocity of the propagating spin wave can be varied by varying at least one of the magnitude and direction of a magnetic bias field within the material, the material being further adapted to receive an applied magnetic field which in combination with the magnetic characteristics of the material provides the internal magnetic bias field needed to effect spatial conversion from electromagnetic power to propagating spin waves, the spin waves being carried in the electromagnetic channel, the quantum mechanical exchange channel or a combination thereof, the material being doped to provide a predetermined grading of said magnetic characteristics thereby to provide a predetermined profile of internal magnetic bias field, said material being a thin film comprising a plurality of adjacent layers disposed along the path of travel of the propagating wave energy within the material, the magnetic characteristics of the material differing from layer to layer thereby to provide said abrupt discontinuity as a series of smaller discontinuities.
Claim 5
Dependent Claim
143 words
An article for processing electromagnetic wave energy, that comprises, a magnetic material adapted to receive the electromagnetic wave energy, the material being one that will support propagating spin wave energy and propagating elastic wave energy, the material being one in which the electromagnetic wave energy can be converted to propagating spin wave energy and elastic wave energy, the material being further adapted to receive an applied magnetic field which in combination with the magnetic characteristics of the material provides the internal magnetic bias field needed to effect spatial conversion from electromagnetic power to propagating spin waves and elastic waves, the material being treated to provide a predetermined grading of said magnetic characteristics, said material being rod-like in form and the regions at the end faces thereof being doped to form a graded thin film *50 to 100 microns thick at each end face.
Claim 6
Dependent Claim
32 words
An article as claimed in claim 6 in which the crystal is YIG and in which the saturation magnetization 4 pi Ms of the film varies from 1,430 oersteds to 350 oersteds.
Claim 7
Dependent Claim
172 words
An article for processing electromagnetic wave energy, that comprises, a magnetic material adapted to receive the electromagnetic wave energy, the material being one that will support propagating spin wave energy and propagating elastic wave energy, the material being one in which the electromagnetic wave energy can be converted to propagating spin wave energy and elastic wave energy; the material being further adapted to receive an applied magnetic field which in combination with the magnetic characteristics of the material provides the internal magnetic bias field needed to effect spatial conversion from electromagnetic power to propagating spin waves and elastic waves, the material being treated to provide a predetermined grading of said magnetic characteristics, said material having two end faces separated by an interior portion, said end faces containing a thin film of non-uniform material parameters to give graded values of material saturation 4 pi Ms at said end faces, the graded values of the thin film acting with said applied magnetic filed to provide the desired contour of the internal magnetic bias field.
Claim 8
Dependent Claim
51 words
An article as claimed in claim 8 in which said material is a crystal which contains at said end faces controlled gradients of the concentration of impurities, thereby to control the frequency and/or wavelength dependent susceptibility within the crystal at the region of said end faces and within said thin film.
Claim 9
Dependent Claim
28 words
An article as claimed in claim 9 in which the thin film at each of the end faces is on the order of *50 to 100 microns thick.
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) | 1977-05-20 | 1977-11-19 | 1978-05-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-05-20 | 1981-11-19 | 1982-05-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-05-20 | 1985-11-19 | 1986-05-21 | $7700.00 | Window Closed / Lapsed |