US5153762A
Expired / Lapsed
US
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Method and apparatus for recovering AM channell signals distributed on an optical fiber
Assignee: Ciena Corp
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Filing: 1990-03-19
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Granted: 1992-10-06
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Expires: 2010-03-19
Abstract
Abstract Individual AM channel signals are recovered in the optical domain from a band of signals distributed on an optical fiber. A semiconductor optical amplifier is coupled to receive the band of optical channel signals. The band is defined by a lowest channel frequency f L and a highest channel frequency f H wherein f H <2f L . A local oscillator modulates the gain of the amplifier with a frequency that translates a selected channel signal to another frequency outside of the band for subsequent processing in the electrical domain.
Inventors
- 👤 David R. Huber
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 06:06
CPC Classifications
H; H04; H04B; H04B10/00; H04B10/60; H04B10/27; H04B10/272; H04N; H04N7/00; H04N7/22
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
119 words
A method for distributing multichannel AM subcarrier modulated information on an optical fiber for subsequent recovery comprising the steps of: providing a plurality of AM channel signals in a frequency band defined by a lowest channel frequency f L and a highest channel frequency f H wherein f H<2f L ; intensity modulating a light source with said band of signals to provide an AM subcarrier modulated optical signal; transmitting said optical signal over an optical fiber; receiving the transmitted optical signal from said fiber; amplifying the received signal in a semiconductor optical amplifier; and modulating said amplifier at a local oscillator frequency to translate a channel signal contained in the received signal to a predetermined frequency for recovery.
Claim 2
Independent Claim
119 words
A method for distributing multichannel AM subcarrier modulated information on an optical fiber for subsequent recovery comprising the steps of: providing a plurality of AM channel signals in a frequency band defined by a lowest channel frequency f L and a highest channel frequency f H wherein f H<2f L ; intensity modulating a light source with said band of signals to provide an AM subcarrier modulated optical signal; transmitting said optical signal over an optical fiber; receiving the transmitted optical signal from said fiber; amplifying the received signal in a semiconductor optical amplifier; and modulating said amplifier at a local oscillator frequency to translate a channel signal contained in the received signal to a predetermined frequency for recovery.
Claim 3
Dependent Claim
19 words
The method of claim 1 wherein said local oscillator frequency is chosen to translate the channel signal to baseband.
Claim 4
Dependent Claim
24 words
The method of claim 1 comprising the further step of: tuning said local oscillator frequency to selectively recover different channel signals from said plurality.
Claim 5
Dependent Claim
28 words
The method of claim 3 comprising the further step of: converting an optical channel signal output from said amplifier to an electrical signal for recovery by a receiver.
Claim 6
Dependent Claim
13 words
The method of claim 4 wherein said channel signals comprise AM-VSB video signals.
Claim 7
Dependent Claim
17 words
The method of claim 5 wherein said frequency band extends from about 505.25 MHz to 997.25 MHz.
Claim 8
Dependent Claim
13 words
The method of claim 1 wherein said channel signals comprise AM-VSB video signals.
Claim 9
Dependent Claim
109 words
Apparatus for recovering individual AM channel signals from a band of signals distributed on an optical fiber comprising: a semiconductor optical amplifier having a gain; means for coupling said amplifier to receive a plurality of AM optical channel signals from an optical fiber in a frequency band defined by a lowest channel frequency f L and a highest channel frequency f H wherein f H <2f L ; a local oscillator; and means for modulating the gain of said amplifier with a frequency output from said local oscillator, wherein said modulation translates a channel signal in said plurality to another frequency outside said band for output from the amplifier.
Claim 10
Dependent Claim
109 words
Apparatus for recovering individual AM channel signals from a band of signals distributed on an optical fiber comprising: a semiconductor optical amplifier having a gain; means for coupling said amplifier to receive a plurality of AM optical channel signals from an optical fiber in a frequency band defined by a lowest channel frequency f L and a highest channel frequency f H wherein f H <2f L ; a local oscillator; and means for modulating the gain of said amplifier with a frequency output from said local oscillator, wherein said modulation translates a channel signal in said plurality to another frequency outside said band for output from the amplifier.
Claim 11
Dependent Claim
23 words
The apparatus of claim 8 further comprising: means for converting a translated optical channel signal output from the amplifier to an electrical signal.
Claim 12
Dependent Claim
12 words
The apparatus of claim 9 wherein said converting means comprises a photodetector.
Claim 13
Dependent Claim
13 words
The apparatus of claim 10 wherein said channel signals comprise AM-VSB video signals.
Claim 14
Dependent Claim
22 words
The apparatus of claim 11 further comprising: means for coupling a converted channel signal output from said photodetector to a television receiver.
Claim 15
Dependent Claim
24 words
The apparatus of claim 11 further comprising: means for tuning said local oscillator output frequency to selectively recover individual channel signals from said plurality.
Claim 16
Dependent Claim
13 words
The apparatus of claim 8 wherein said channel signals comprise AM-VSB video signals.
Claim 17
Dependent Claim
24 words
The apparatus of claim 14 further comprising: means for tuning said local oscillator output frequency to selectively recover individual channel signals from said plurality.
Claim 18
Dependent Claim
30 words
The apparatus of claim 8 further comprising: means for tuning said local oscillator output frequency within a predetermined range to selectively translate individual channel signals from said plurality to baseband.
Claim 19
Dependent Claim
13 words
The apparatus of claim 16 wherein said channel signals comprise AM-VSB video signals.
Claim 20
Dependent Claim
23 words
The apparatus of claim 17 further comprising: means for converting a baseband optical channel signal output from the amplifier to an electrical signal.
Claim 21
Dependent Claim
12 words
The apparatus of claim 18 wherein said converting means comprises a photodetector.
Claim 22
Dependent Claim
23 words
The apparatus of claim 19 further comprising: means for coupling a baseband electrical channel signal output from said photodetector to a television receiver.
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) | 1995-10-06 | 1996-04-06 | 1996-10-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-10-06 | 2000-04-06 | 2000-10-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-10-06 | 2004-04-06 | 2004-10-06 | $7700.00 | Window Closed / Lapsed |