US3755676A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Spacially multiplexed optical beam communication system
Assignee: AT&T Inc
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Filing: 1972-01-24
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Granted: 1973-08-28
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Expires: 1992-01-24
Abstract
Abstract A plurality of optical beams, encoded to have different spacially varying intensity profiles, are launched along a common wavepath. At the receiver, demultiplexing is effected by means of a converging lens which performs a two-dimensional Fourier transformation upon the multiplexed beams, producing an array of spots at the focal plane of the lens which uniquely identifies and separates the plurality of beams. It is an advantage of such a system that the spot locations are not affected by small displacements of the beams off the path axis.
Inventors
- 👤 T Kinsel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 23:44
CPC Classifications
G; G02; G02B; G02B27/00; G02B27/42; G02B27/46; G02B6/00; G02B6/24; G02B6/26; G02B6/28; G02B6/293; G02B6/29344; H; H04; H04B; H04B10/00
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
102 words
A spacially multiplexed, optical wave communication system comprising: a transmitter; a receiver; and a wavepath connecting said transmitter to said receiver; said transmitter including: means for generating a plurality of optical beams; encoding means for impressing a different spacial modulation upon the intensity profile of each of said beams; and means for spacially multiplexing said beams for propagation along said wavepath; said receiver including a demultiplexer comprising: a converging lens for performing a two-dimensional Fourier transformation upon said beams, producing for each beam a unique array of beam components; and means for coupling said beam components to the rest of said receiver.
Claim 2
Dependent Claim
102 words
A spacially multiplexed, optical wave communication system comprising: a transmitter; a receiver; and a wavepath connecting said transmitter to said receiver; said transmitter including: means for generating a plurality of optical beams; encoding means for impressing a different spacial modulation upon the intensity profile of each of said beams; and means for spacially multiplexing said beams for propagation along said wavepath; said receiver including a demultiplexer comprising: a converging lens for performing a two-dimensional Fourier transformation upon said beams, producing for each beam a unique array of beam components; and means for coupling said beam components to the rest of said receiver.
Claim 3
Dependent Claim
50 words
The system in accordance with claim 1 wherein: said encoding means comprises a plurality of gratings, each having a sinusoidally varying transmittance characteristic along a first transverse direction normal to the direction of beam propagation, and a constant transmittance characteristic along a second transverse direction normal to said First direction.
Claim 4
Dependent Claim
21 words
The system in accordance with claim 2 wherein: the transmittance characteristic of each of said gratings has a different spacial frequency.
Claim 5
Dependent Claim
23 words
The system in accordance with claim 2 wherein: the direction along which said transmittance varies is different for different ones of said gratings.
Claim 6
Dependent Claim
32 words
The system in accordance with claim 1 wherein: said wavepath includes an odd number of converging lenses; and wherein said converging lens of said demultiplexer is the last lens in said wavepath.
Claim 7
Dependent Claim
22 words
The system in accordance with claim 1 wherein: said converging lens is disposed between said wavepath and the rest of said receiver.
Claim 8
Dependent Claim
30 words
The system in accordance with claim 1 wherein: said coupling means includes a plurality of optical fibers whose input ends are located in the focal plane of said converging lens.
Claim 9
Dependent Claim
25 words
The system in accordance with claim 1 wherein: said coupling means includes a plurality of photodetectors located in the focal plane of said converging lens.
Claim 10
Dependent Claim
58 words
In an optical communication system, the combination comprising: means for producing a plurality of optical beams; means for encoding each of said beams with a different spacial modulation; means for combining said beams for transmission along a common wavepath; and means for demultiplexing said beams including a convex lens for performing a two-dimensional Fourier transformation upon said beams.
Claim 11
Dependent Claim
58 words
In an optical communication system, the combination comprising: means for producing a plurality of optical beams; means for encoding each of said beams with a different spacial modulation; means for combining said beams for transmission along a common wavepath; and means for demultiplexing said beams including a convex lens for performing a two-dimensional Fourier transformation upon said beams.
References Cited (Backward Citations)
US3532890A
Cited
US3612658A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-08-27 | 1977-02-26 | 1977-08-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-08-27 | 1981-02-26 | 1981-08-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-08-27 | 1985-02-26 | 1985-08-28 | $7700.00 | Window Closed / Lapsed |