US4349796A
Expired / Lapsed
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Devices incorporating phonon filters
Assignee: AT&T Inc
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Filing: 1980-12-15
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Granted: 1982-09-14
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Expires: 2000-12-15
Abstract
Abstract An acoustic superlattice of alternating layers of different acoustic impedance is disclosed as a filter for high frequency phonons. Applications discussed include spectrometers, acoustic imaging apparatus, and cavity resonators.
Inventors
- 👤 Maurice A. Chin
- 👤 Venkatesh Narayanamurti
- 👤 Horst L. Stormer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 23:21
CPC Classifications
G; G01; G01H; G01H3/00; G01H3/10; G01H3/12; G01H3/125; G10; G10K; G10K11/00; G10K11/02; G10K11/04; Y; Y10; Y10S; Y10S505/00; Y10S505/825; Y10S505/866
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
81 words
A phonon device comprising a semiconductor body in which phonons over a range of wavelengths can be made to propagate simultaneously, source means coupled to said body for exciting said phonons to propagate therein, and filter means coupled to said body so as to intercept said phonons and to transmit phonons in a particular sub-range of said wavelengths and to reflect phonons outside said sub-range, said filter means comprising an acoustic superlattice of essentially lattice-matched semiconductor layers of alternating acoustic impedance.
Claim 2
Dependent Claim
81 words
A phonon device comprising a semiconductor body in which phonons over a range of wavelengths can be made to propagate simultaneously, source means coupled to said body for exciting said phonons to propagate therein, and filter means coupled to said body so as to intercept said phonons and to transmit phonons in a particular sub-range of said wavelengths and to reflect phonons outside said sub-range, said filter means comprising an acoustic superlattice of essentially lattice-matched semiconductor layers of alternating acoustic impedance.
Claim 3
Dependent Claim
19 words
The device of claim 1 including detector means coupled to said body so as to intercept said transmitted phonons.
Claim 4
Dependent Claim
19 words
The device of claim 1 including detector means coupled to said body so as to intercept said reflected phonons.
Claim 5
Independent Claim
21 words
The device of claims 2 or 3 wherein said source means and said detector means each includes a superconducting tunnel junction.
Claim 6
Dependent Claim
22 words
The device of claim 4 wherein the superconducting energy gap of said detector means is smaller than that of said source means.
Claim 7
Dependent Claim
32 words
The device of claim 4 wherein said source means and said detector means are formed on opposite major surfaces of said body, said detector means being adapted to detect said transmitted phonons.
Claim 8
Dependent Claim
23 words
The device of claim 4 wherein said source means and said detector means are formed on the same major surface of said body.
Claim 9
Dependent Claim
56 words
The device of claim 7 for imaging an object further including lens means on said body for focusing said transmitted phonons onto said object, phonons reflected by said object being re-transmitted through said acoustic superlattice to said detector means, and means for causing said transmitted phonons to be sequentially incident on different portions of said object.
Claim 10
Dependent Claim
29 words
The device of claim 8 wherein said body includes a buffer layer adjacent said superlattice and said lens means includes a concave curved surface formed in said buffer layer.
Claim 11
Dependent Claim
24 words
The device of claim 8 further including means for submersing at least said object, said body and said tunnel junctions in a cryogenic liquid.
Claim 12
Dependent Claim
28 words
The device of claim 1 wherein said acoustic superlattice comprises pairs of adjacent layers of Al x Ga 1-x As and Al y Ga 1-y As (0≦x,y≦1, x≠y).
Claim 13
Dependent Claim
63 words
The device of claim 3 for use as an acoustic spectrometer wherein said source means and said detector means are formed on the same major surface of said body, said source means generating phonons at a plurality of wavelengths, said acoustic superlattice reflecting those wavelengths which satisfy the Bragg condition and said detector means receiving phonons of selected ones of said reflected wavelengths.
Claim 14
Dependent Claim
56 words
The device of claim 12 wherein said detector means comprises a plurality n of detectors arranged in tandem on said major surface so that the i th detector (i=1,2 . . . n) receives essentially only phonons of wavelength λ i which are reflected from said superlattice at an angle α i satisfying the Bragg condition.
Claim 15
Dependent Claim
67 words
The device of claim 12 wherein said source means comprises a thin metal film arranged on said surface and further including an energy beam source for scanning said film to sequentially generate phonons at different places in said body, for each position of said beam said detector means receiving essentially only phonons of a particular wavelength which are reflected from said superlattice and satisfy the Bragg condition.
Claim 16
Dependent Claim
20 words
The device of claim 14 wherein said film is segmented and said beam is made to scan said segments sequentially.
Claim 17
Dependent Claim
59 words
An acoustic cavity resonator comprising a pair of acoustic superlattice mirrors comprising essentially lattice-matched semiconductor layers of alternating acoustic impedance, a semiconductor zone intermediate to and contiguous with said acoustic superlattice mirrors, and source means for exciting phonons in said zone, whereby only phonons of particular wavelengths reflected by said mirrors resonate in a direction orthogonal to said mirrors.
Claim 18
Dependent Claim
59 words
An acoustic cavity resonator comprising a pair of acoustic superlattice mirrors comprising essentially lattice-matched semiconductor layers of alternating acoustic impedance, a semiconductor zone intermediate to and contiguous with said acoustic superlattice mirrors, and source means for exciting phonons in said zone, whereby only phonons of particular wavelengths reflected by said mirrors resonate in a direction orthogonal to said mirrors.
Claim 19
Dependent Claim
20 words
The resonator of claim 16 wherein said source means comprises means for applying electric current or voltage to said zone.
Claim 20
Dependent Claim
21 words
The reasonator of claim 16 wherein said source means comprising a source of optical radiation which is absorbed by said zone.
Claim 21
Dependent Claim
37 words
The resonator of claim 18 wherein at least one of said superlattices is made transparent to said radiation, said zone absorbs said radiation and said radiation is directed through said at least one superlattice into said zone.
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) | 1985-09-13 | 1986-03-15 | 1986-09-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-09-13 | 1990-03-15 | 1990-09-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-09-13 | 1994-03-15 | 1994-09-14 | $7700.00 | Window Closed / Lapsed |