Patent CA705747A successfully refreshed from Google Patents.
US5222089A
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US
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Optical signal source for overcoming distortion generated by an optical amplifier
Assignee: Ciena Corp
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Filing: 1992-01-08
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Granted: 1993-06-22
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Expires: 2012-01-08
Abstract
Abstract An amplified signal source is provided for transmitting modulated information signals over a fiber optic communication link, which may have high fiber dispersion. A continuous wave laser produces an optical carrier at a wavelength λ 1 . The optical carrier is intensity modulated to provide a substantially chirp free output signal. The output signal is amplified in an optical amplifier and coupled for transmission over a link fiber that can have a minimum dispersion at a wavelength λ 2 that is different than λ 1 . The nonzero gain slope of the optical amplifier does not significantly degrade the substantially chirp free output signal.
Inventors
- 👤 David R. Huber
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 17:26
CPC Classifications
H; H04; H04B; H04B10/00; H04B10/29; H04B10/291; H04B10/25; H04B10/2507; H04B10/2513; H04B10/25137; H04B10/2912
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
133 words
A signal source for the transmission of an amplitude modulated information signal over a fiber optic communication link comprising: a continuous wave laser for producing an optical carrier at a wavelength λ 1 ; means for combining said optical carrier with an information signal to intensity modulate said optical carrier substantially free from optical frequency chirp; an optical amplifier having a nonzero gain slope coupled to receive and amplify the intensity modulated optical carrier; and means for coupling the modulated optical carrier for transmission over a link fiber; wherein said intensity modulated optical carrier, substantially free from optical frequency chirp, and said amplifier, which has a nonzero gain slope, provide said signal for transmission with a composite second order distortion, (CSO) of 60 decibels below carrier, (dBc) or better along said link fiber.
Claim 2
Dependent Claim
133 words
A signal source for the transmission of an amplitude modulated information signal over a fiber optic communication link comprising: a continuous wave laser for producing an optical carrier at a wavelength λ 1 ; means for combining said optical carrier with an information signal to intensity modulate said optical carrier substantially free from optical frequency chirp; an optical amplifier having a nonzero gain slope coupled to receive and amplify the intensity modulated optical carrier; and means for coupling the modulated optical carrier for transmission over a link fiber; wherein said intensity modulated optical carrier, substantially free from optical frequency chirp, and said amplifier, which has a nonzero gain slope, provide said signal for transmission with a composite second order distortion, (CSO) of 60 decibels below carrier, (dBc) or better along said link fiber.
Claim 3
Dependent Claim
18 words
A signal source in accordance with claim 1 wherein said optical amplifier comprises a rare earth fiber amplifier.
Claim 4
Dependent Claim
15 words
A signal source in accordance with claim 2 wherein said laser is an Erbium laser.
Claim 5
Dependent Claim
17 words
A signal source in accordance with claim 3 wherein said wavelength λ 1 is about 1.5 microns.
Claim 6
Dependent Claim
17 words
A signal source in accordance with claim 4 wherein said combining means comprise an external optical modulator.
Claim 7
Dependent Claim
26 words
A signal source in accordance with claim 5 wherein said external optical modulator is a Mach-Zehnder modulator that is balanced to substantially eliminate optical frequency chirp
Claim 8
Dependent Claim
17 words
A signal source in accordance with claim 1 wherein said combining means comprise an external optical modulator.
Claim 9
Dependent Claim
26 words
A signal source in accordance with claim 7 wherein said external optical modulator is a Mach-Zehnder modulator that is balanced to substantially eliminate optical frequency chirp.
Claim 10
Dependent Claim
34 words
A signal source in accordance with claim 7 wherein said information signal is a VSB-AM video signal, said signal source further comprising means for conditioning said video signal to linearize said external optical modulator.
Claim 11
Dependent Claim
23 words
A signal source in accordance with claim 9 wherein said conditioning means predistort said video signal for input to said external optical modulator.
Claim 12
Dependent Claim
26 words
A signal source in accordance with claim 10 wherein said external optical modulator is a Mach-Zehnder modulator that is balanced to substantially eliminate optical frequency chirp.
Claim 13
Dependent Claim
28 words
A signal source in accordance with claim 1 wherein said link fiber has a minimum dispersion at a wavelength λ 2 that is different than λ 1 .
Claim 14
Dependent Claim
80 words
A signal source in accordance with claim 12 wherein: said laser is an Erbium laser operating at a wavelength λ 1 of about 1.5 microns; said link fiber has a minimum dispersion at a wavelength λ 2 of about 1.3 microns; and said combining means comprise a substantially chirp free external optical modulator having an optical input for receiving said optical carrier, an electrical input for receiving said information signal, and an optical output for outputting the modulated optical carrier.
Claim 15
Dependent Claim
16 words
A signal source in accordance with claim 13 wherein said link fiber is single mode fiber.
Claim 16
Dependent Claim
26 words
A signal source in accordance with claim 13 wherein said external optical modulator is a Mach-Zehnder modulator that is balanced to substantially eliminate optical frequency chirp.
Claim 17
Dependent Claim
81 words
A signal source in accordance with claim 12 wherein: said laser is a rare earth laser operating at a wavelength λ 1 of about 1.3 microns; said link fiber has a minimum dispersion at a wavelength λ 2 of about 1.5 microns; and said combining means comprise a substantially chirp free external optical modulator having an optical input for receiving said optical carrier, an electrical input for receiving said information signal, and an optical output for outputting the modulated optical carrier.
Claim 18
Dependent Claim
16 words
A signal source in accordance with claim 16 wherein said link fiber is dispersion shifted fiber.
Claim 19
Dependent Claim
26 words
A signal source in accordance with claim 16 wherein said external optical modulator is a Mach-Zehnder modulator that is balanced to substantially eliminate optical frequency chirp.
References Cited (Backward Citations)
No citation records indexed.
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