US4075474A
Expired / Lapsed
US
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Method and apparatus for distortion reduction in optical communication systems
Assignee: Nortel Networks Ltd
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Filing: 1977-04-19
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Granted: 1978-02-21
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Expires: 1997-04-19
Abstract
Abstract An optical transmitter suitable for analog transmission in optic fiber communication systems utilizes two matched light emitting diodes to achieve distortion reduction.
Inventors
- 👤 Jozef Straus
- 👤 Otto Istvan Szentesi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 11:26
CPC Classifications
H; H04; H04B; H04B10/00; H04B10/50; H04B10/501; H04B10/502; H04B10/25; H04B10/2507; H04B10/564
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
100 words
An optical transmitter having two parallel signal paths and comprising: signal dividing means for coupling a first component of an electrical input signal to a first of said signal paths, and a second component of said input signal to a second of said signal paths; said first signal path including a first electrical-to-optical converter optically coupled to an optical-to-electrical converter; said second signal path providing a predetermined electrical delay; means providing the instantaneous difference between signals at the ends of said first and second signal paths; and a second electrical-to-optical converter for converting said instantaneous difference into an optical output.
Claim 2
Dependent Claim
100 words
An optical transmitter having two parallel signal paths and comprising: signal dividing means for coupling a first component of an electrical input signal to a first of said signal paths, and a second component of said input signal to a second of said signal paths; said first signal path including a first electrical-to-optical converter optically coupled to an optical-to-electrical converter; said second signal path providing a predetermined electrical delay; means providing the instantaneous difference between signals at the ends of said first and second signal paths; and a second electrical-to-optical converter for converting said instantaneous difference into an optical output.
Claim 3
Dependent Claim
39 words
The optical transmitter according to claim 1, said first and second electrical-to-optical converters having similar electrical-to-optical transfer characteristics, and said delay provided by said second optical path being substantially equal to the total delay of said first signal path.
Claim 4
Dependent Claim
26 words
The optical transmitter according to claim 2, said first and second electrical-to-optical converter being semiconductor light emitting diodes, and said optical-to-electrical converter being a semiconductor photodiode.
Claim 5
Dependent Claim
19 words
The optical transmitter according to claim 3, said second signal path including means for adjusting the signal power therethrough.
Claim 6
Dependent Claim
23 words
The optical transmitter according to claim 1, said first component of said input signal containing half the power contained in said second component.
Claim 7
Dependent Claim
23 words
The optical transmitter according to claim 2, said first component of said input signal containing half the power contained in said second component.
Claim 8
Dependent Claim
23 words
The optical transmitter according to claim 3, said first component of said input signal containing half the power contained in said second component.
Claim 9
Dependent Claim
55 words
The optical transmitter according to claim 1, said signals at the ends of said first and second signal paths containing signal powers in the ratio of (K+1):G, G being the quotient of the power at the end of said first signal path by the power at its beginning, and K being a predetermined real number.
Claim 10
Dependent Claim
55 words
The optical transmitter according to claim 2, said signals at the ends of said first and second signal paths containing signal powers in the ratio of (K+1):G, G being the quotient of the power at the end of said first signal path by the power at its beginning, and K being a predetermined real number.
Claim 11
Dependent Claim
55 words
The optical transmitter according to claim 3, said signals at the ends of said first and second signal paths containing signal powers in the ratio of (K+1):G, G being the quotient of the power at the end of said first signal path by the power at its beginning, and K being a predetermined real number.
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) | 1981-02-20 | 1981-08-22 | 1982-02-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-02-20 | 1985-08-22 | 1986-02-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-02-20 | 1989-08-22 | 1990-02-21 | $7700.00 | Window Closed / Lapsed |