Patent JPS5622505A successfully refreshed from Google Patents.
US3777149A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Signal detection and delay equalization in optical fiber transmission systems
Assignee: AT&T Inc
•
Filing: 1972-07-17
•
Granted: 1973-12-04
•
Expires: 1992-07-17
Abstract
Abstract A stripper at the end of an optical fiber selectively couples propagating signal components out of the fiber at characteristic angles. A linear array of photodetectors selectively responds to each of the coupled signal components or to groups of such components. When used simply as a mode or as a frequency separator, the detected signals are separately coupled to different output circuits. In a detector-equalizer embodiment, the signals, suitably delayed relative to each other, are coupled to a common output circuit.
Inventors
- 👤 E Marcatili
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 11:39
CPC Classifications
G; G02; G02B; G02B6/00; G02B6/24; G02B6/42; G02B6/4201; G02B6/4249; G02B6/425; G02B6/10; G02B6/14; G02B6/26; G02B6/268; G02B6/4204; G02B6/4206; G02B6/4215; G02B6/28; G02B6/2804; G02B6/2852
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
91 words
A signal detector arrangement for use with an optical fiber waveguide having an inner core and outer cladding, including: a stripper for coupling wave Energy out of said fiber, comprising a slab of dielectric material in coupling relationship with said core, where the refractive index of said material is equal to or greater than the index of said core; and an array of photodetectors disposed adjacent to said stripper where each photodetector is dimensioned and oriented to intercept wave energy coupled out of said fiber within a different range of angles.
Claim 2
Dependent Claim
91 words
A signal detector arrangement for use with an optical fiber waveguide having an inner core and outer cladding, including: a stripper for coupling wave Energy out of said fiber, comprising a slab of dielectric material in coupling relationship with said core, where the refractive index of said material is equal to or greater than the index of said core; and an array of photodetectors disposed adjacent to said stripper where each photodetector is dimensioned and oriented to intercept wave energy coupled out of said fiber within a different range of angles.
Claim 3
Dependent Claim
38 words
The arrangement according to claim 1 wherein said fiber is a multimode waveguide; and wherein each detector intercepts wave energy associated with one of the modes guided along said fiber, or with a selected group of said modes.
Claim 4
Dependent Claim
23 words
The arrangement according to claim 1 wherein said fiber is a single mode waveguide; and wherein each detector intercepts different frequency wave energy.
Claim 5
Dependent Claim
17 words
The arrangement according to claim 1 wherein each of said detectors is coupled to an output circuit.
Claim 6
Dependent Claim
24 words
The arrangement according to claim 1 including a common output circuit; and means for coupling each of said detectors to said common output circuit.
Claim 7
Dependent Claim
23 words
The arrangement according to claim 5 wherein said coupling means includes delay networks for compensating for the delay distortion produced in said fiber.
Claim 8
Dependent Claim
16 words
The arrangement according to claim 1 wherein each of said photodetectors is a Schottky barrier photodiode.
Claim 9
Dependent Claim
53 words
The arrangement according to claim 2 including means for focusing the wave energy associated with a different one of said modes, or with a different selected group of said modes onto each of said photodetectors; and wherein said photodetectors are located at the focal plane of said focusing means for said different modes.
Claim 10
Dependent Claim
52 words
A detector-equalizer for use with a multimode optical fiber waveguide comprising: a signal detector arrangement in accordance with claim 1; a common output circuit; and means including delay networks for coupling the output signals from said array of photodetectors to said output circuit to minimize the delay distortion introduced by said fiber.
Claim 11
Dependent Claim
39 words
The detector-equalizer according to claim 9 wherein the means for coupling the output signals from the photodetectors responsive to the faster propagating modes include delay networks for equalizing the total average delay for all of said groups of modes.
Claim 12
Dependent Claim
13 words
The detector-equalizer according to claim 8 wherein said coupling means include signal amplifiers.
References Cited (Backward Citations)
US3584230A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-12-03 | 1977-06-04 | 1977-12-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-12-03 | 1981-06-04 | 1981-12-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-12-03 | 1985-06-04 | 1985-12-04 | $7700.00 | Window Closed / Lapsed |