US3679904A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Multiple beam transmissions system with improved cross-talk reduction
Assignee: AT&T Inc
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Filing: 1969-03-03
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Granted: 1972-07-25
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Expires: 1989-03-03
Abstract
Abstract Improved cross-talk reduction with spatial multiplexing of a plurality of N beams in a beam transmission system comprising a sequence of confocally spaced lenses is accomplished by inserting saturable absorption cells in anti-nodal regions of the transmission system, at which regions the beams are spatially distinct. The beams are resolved at the output end into N separate beams. A similar arrangement can be employed using nonconfocally spaced lenses. In a pulse-code-modulation communication system, the saturable absorption cells sharpen the pulses time-wise as well as space-wise.
Inventors
- 👤 Daniel Weiner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 23:43
CPC Classifications
H; H04; H04B; H04B10/00; H04B10/80; H04B10/85
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
133 words
Optical communication apparatus comprising a plurality of optical transmitters arranged in an array to provide initially distinct beams, a plurality of detectors arranged in an array at a location remote from said transmitters, a plurality of lenses disposed in tandem with respective ones of said transmitters to direct a plurality of said initially distinct beams to overlap in at least a first region between said transmitters and said detectors, a plurality of axially spaced means between said lenses and said detectors for focusing said beams to image said transmitters upon respective ones of said detectors, and means between the axially spaced means at second regions in which said beams are spatially distinct for absorbing portions of said beams below a selected level and passing the portions of said beams above said selected level.
Claim 2
Dependent Claim
133 words
Optical communication apparatus comprising a plurality of optical transmitters arranged in an array to provide initially distinct beams, a plurality of detectors arranged in an array at a location remote from said transmitters, a plurality of lenses disposed in tandem with respective ones of said transmitters to direct a plurality of said initially distinct beams to overlap in at least a first region between said transmitters and said detectors, a plurality of axially spaced means between said lenses and said detectors for focusing said beams to image said transmitters upon respective ones of said detectors, and means between the axially spaced means at second regions in which said beams are spatially distinct for absorbing portions of said beams below a selected level and passing the portions of said beams above said selected level.
Claim 3
Dependent Claim
21 words
Optical communication apparatus according to claim 1 in which the absorbing means comprise at least one cell containing saturable absorbing material.
Claim 4
Dependent Claim
28 words
Optical communication apparatus according to claim 2 including a plurality of coherent light amplifiers cascaded with said cell in the second in which the beams are spatially distinct.
Claim 5
Dependent Claim
50 words
Optical communication apparatus according to claim 3 in which the transmitters comprise optical pulse-code-modulation transmitters, the cascaded amplifiers and absorption cell being mutually adapted to make the selected level exceed an expected noise level associated with the optical pulses, said amplifiers and cells simultaneously sharpening the pulses space-wise and time-wise.
Claim 6
Dependent Claim
49 words
Optical communication apparatus according to claim 1 including a plurality of means interspersed with said focusing means at axially spaced different second regions in which said beams are spatially distinct for absorbing portions of said beam below selected levels and passing portions of said beams above said selected levels.
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) | 1975-07-25 | 1976-01-24 | 1976-07-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-07-25 | 1980-01-24 | 1980-07-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-07-25 | 1984-01-24 | 1984-07-25 | $7700.00 | Window Closed / Lapsed |