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US4824201A
Expired / Lapsed
US
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Simultaneous transmission of LED and laser signals over single mode fiber
Assignee: STANFORD UNIVERSITY OTL LLC
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Filing: 1987-07-13
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Granted: 1989-04-25
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Expires: 2007-07-13
Abstract
Abstract At the transmitting end of an optical transmission system, a wide linewidth LED (31) is intensity modulated by a first digital information signal and a narrow linewidth DFB (Distributed Feedback) laser (32) is frequency modulated by a second digital information signal and the two modulated optical signals are combined (33) for transmission over a single mode optical fiber (34). At the receiving end, the intensity modulating digital signal is recovered from the received optical signal by a photodetctor (52). The frequency modulating digital signal is recovered by a coherent receiver (53) which includes a local oscillator (55) the output of which is optically combined (54) with the received optical signal. A photodetector (56) converts this combined optical signal to an electrical IF signal, and an IF demodulator (57) reconstructs the second digital signal therefrom.
Inventors
- 👤 Leonid G. Kazovsky
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 22:08
CPC Classifications
H; H04; H04J; H04J14/00; H04J14/02; H04J14/0226; H04B; H04B10/00; H04B10/50; H04B10/501; H04B10/502; H04B10/516; H04B10/54; H04J14/0227; H04J14/0241; H04J14/0242; H04J14/0245; H04J14/0246; H04J14/0249; H04J14/025; H04J14/0278; H04J14/0279
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
132 words
An optical transmission system for simultaneously transmitting plural digital signals between a transmitting end and a receiving end over a single mode optical fiber comprising: at the transmitting end, a wide linewidth optical device for intensity modulating a first of said digital signals, a narrow linewidth optical device for angle modulating a second of said digital signals, and means for combining the outputs of said wide and narrow linewidth optical devices for transmission over the single mode fiber, and at the receiving end, means for recovering the first of said digital signals by detecting the intensity variations in the optical signal received over the single mode fiber, and means for recovering the second of said digital signals by detecting the angle variations in the optical signal received over the single mode fiber.
Claim 2
Dependent Claim
132 words
An optical transmission system for simultaneously transmitting plural digital signals between a transmitting end and a receiving end over a single mode optical fiber comprising: at the transmitting end, a wide linewidth optical device for intensity modulating a first of said digital signals, a narrow linewidth optical device for angle modulating a second of said digital signals, and means for combining the outputs of said wide and narrow linewidth optical devices for transmission over the single mode fiber, and at the receiving end, means for recovering the first of said digital signals by detecting the intensity variations in the optical signal received over the single mode fiber, and means for recovering the second of said digital signals by detecting the angle variations in the optical signal received over the single mode fiber.
Claim 3
Dependent Claim
28 words
A transmission system in accordance with claim 1 wherein said wide linewidth optical device is an LED and said narrow linewidth optical device is a narrow linewidth laser.
Claim 4
Dependent Claim
20 words
A transmission system in accordance with claim 2 wherein said laser FSK (frequency shift keying) modulates and second digital signal.
Claim 5
Dependent Claim
23 words
A transmission system in accordance with claim 3 wherein said means for recovering the second of said digital signals comprises a coherent receiver.
Claim 6
Dependent Claim
65 words
A transmission system in accordance with claim 4 wherein said coherent receiver comprises a local optical oscillator, means for combining the received optical signal with the output of said local oscillator, means for converting to an IF (intermediated frequency) FSK electrical signal the output of said combining means in said receiver and means for demodulating the FSK electrical signal to reconstruct said second digital signal.
Claim 7
Dependent Claim
28 words
A transmission system in accordance with claim 5 further comprising at the receiving end means for electing to recover either said first or second of said digital signals.
Claim 8
Dependent Claim
44 words
A transmissoin system in accordance with claim 5 further comprising at the transmitting end, plural narrow linewidth lasers for FSK modulating plural digital signals, and means for wavelength-division multiplexing the outputs of said plural lasers to form one optical input to said combining means.
Claim 9
Dependent Claim
29 words
A transmission system in accordance with claim 7 further comprising at the receiving end, plural coherent receivers for recovering said plural digital signals wavelength-division multiplexed on said plural lasers.
Claim 10
Dependent Claim
30 words
A transmission system in accordance with claim 8 further comprising at the receiving end, a tunable local oscillator for selectively recovering said digital signals wavelength-division multiplexed on said plural lasers.
Claim 11
Dependent Claim
22 words
A transmission system in accordance with claim 1 wherein said means for recovering the first of said digital signal comprises a photodetector.
Claim 12
Dependent Claim
78 words
For use in an optical transmission system which transmits plural digital signals over a single mode optical fiber between a transmitting end and a receiving end, said transmitting end comprising: a wide linewidth optical device for intensity modulating a first of said digital signals, a narrow linewidth optical device for angle modulating a second of said digital signal, and means for combining the outputs of said wide and narrow linewidth optical device for transmission over the optical fiber.
Claim 13
Dependent Claim
78 words
For use in an optical transmission system which transmits plural digital signals over a single mode optical fiber between a transmitting end and a receiving end, said transmitting end comprising: a wide linewidth optical device for intensity modulating a first of said digital signals, a narrow linewidth optical device for angle modulating a second of said digital signal, and means for combining the outputs of said wide and narrow linewidth optical device for transmission over the optical fiber.
Claim 14
Dependent Claim
33 words
The transmitting end of an optical transmission system in accordance with claim 11 wherein said wide linewidth optical device is an LED and said narrow linewidth optical device is a narrow linewidth laser.
Claim 15
Dependent Claim
22 words
The transmitting end of an optical transmission system in accordance with claim 12 wherein said laser FSK modulates said second digital signal.
Claim 16
Dependent Claim
45 words
The transmitting end of an optical transmission system in accordance with claim 12 further comprising plural narrow linewidth lasers for FSK modulating plural digital signals, and means for wavelength-division multiplexing the outputs of said plural lasers to form one optical input to said combining means.
Claim 17
Dependent Claim
111 words
For use in optical transmission system which transmits plural digital signals over a single mode optical fiber between a transmitting end and a receiving end, a first of said digital signals intensity modulating a wide linewidth optical source and a second of said digital signals angle modulating a narrow linewidth optical source, said narrow and wide linewidth optical sources being combined for transmission over the optical fiber, said receiving end comprising: photodetector means for recovering the first of said digital signals by detecting the intensity variations in said received optical signal, and means for recovering the second of said digital signals by detecting the angle variations in said received optical signal.
Claim 18
Dependent Claim
111 words
For use in optical transmission system which transmits plural digital signals over a single mode optical fiber between a transmitting end and a receiving end, a first of said digital signals intensity modulating a wide linewidth optical source and a second of said digital signals angle modulating a narrow linewidth optical source, said narrow and wide linewidth optical sources being combined for transmission over the optical fiber, said receiving end comprising: photodetector means for recovering the first of said digital signals by detecting the intensity variations in said received optical signal, and means for recovering the second of said digital signals by detecting the angle variations in said received optical signal.
Claim 19
Dependent Claim
21 words
The receiving end in accordance with claim 15 wherein said means for recovering the second digital signal comprises a coherent receiver.
Claim 20
Dependent Claim
75 words
The receiving end in accordance with claim 16 wherein the angle modulation of the second digital is FSK modulation and said coherent receiver comprises a local oscillator, means for combining the received optical signal with the output of said local oscillator, means for converting to an IF (intermediate frequency) FSK electrical signal the output of said combining means in said receiver and means for demodulating the FSK electrical signal to reconstruct said second digital signal.
Claim 21
Dependent Claim
24 words
The receiving end in accordance with claim 16 further comprising means for electing to recover either said first or second of said digital signals.
Claim 22
Dependent Claim
21 words
The receiving end in accordance with claim 15 wherein said means for recovering the second digital signal comprises a non-coherent receiver.
Claim 23
Dependent Claim
103 words
The receiving end in accordance with claim 19 wherein said non-coherent receiver comprises first optical filter means having a frequency passband around the optical frequency associated with the binary "1"s in said second digital signal, second optical filter means having a frequency passband around the optical frequency associated with the binary "0"s in the second digital signal, first and second photodetector means for converting the outputs of said first and second optical filter means, respectively, to electrical signals, and means for reconstructing said second digital signal from the difference between said electrical signals at the outputs of said first and second photodetector means.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1992-04-24 | 1992-10-24 | 1993-04-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-04-24 | 1996-10-24 | 1997-04-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-04-24 | 2000-10-24 | 2001-04-25 | $7700.00 | Window Closed / Lapsed |