US3777150A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Mode detection and delay equalization in multimode optical fiber transmission systems
Assignee: AT&T Inc
•
Filing: 1972-07-17
•
Granted: 1973-12-04
•
Expires: 1992-07-17
Abstract
Abstract This application describes a detector-equalizer circuit for equalizing the dispersion produced in a multimode optical fiber. The circuit comprises an array of photodetectors whose physical configurations conform to the radiation pattern at the end of the optical fiber. The photodetectors selectively respond to each of the modes or to groups of modes propagating along the fiber. The several output signals thus produced are delayed an appropriate amount relative to each other, and then combined in time coincidence in a common output circuit.
Inventors
- 👤 S Miller
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 22:58
CPC Classifications
G; G02; G02B; G02B6/00; G02B6/10; G02B6/14; H; H01; H01P; H01P1/00; H01P1/16; H10; H10F; H10F39/00; H10F39/10; H10F39/107
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
36 words
For use with an optical fiber transmission line, a detector comprising: an array of concentric, circular, photo-responsive regions, each dimensioned to intercept, within different ranges of angles, wave energy radiated at the end of said fiber.
Claim 2
Dependent Claim
36 words
For use with an optical fiber transmission line, a detector comprising: an array of concentric, circular, photo-responsive regions, each dimensioned to intercept, within different ranges of angles, wave energy radiated at the end of said fiber.
Claim 3
Dependent Claim
45 words
The detector according to claim 1 wherein said fiber is a multimode transmission line at the frequencies of interest; and wherein each of said regions intercepts wave energy associated with one of a plurality of guided modes, or with a selected group of said modes.
Claim 4
Dependent Claim
18 words
The detector according to claim 1 wherein each of said photo-responsive regions is coupled to an output circuit.
Claim 5
Dependent Claim
25 words
The detector according to claim 1 including a common output circuit; and means for coupling each of said photo-responsive regions to said common output circuit.
Claim 6
Dependent Claim
23 words
The detector according to claim 1 wherein said coupling means includes delay networks for compensating for the delay distortion produced in said fiber.
Claim 7
Dependent Claim
17 words
The detector according to claim 1 wherein each oF said detector regions comprises a Schottky barrier photo-diode.
Claim 8
Dependent Claim
32 words
The detector according to claim 1 including a segment of optical fiber bonded to said detector such that the longitudinal axis of said fiber is concentric with said array of photo-responsive regions.
Claim 9
Dependent Claim
81 words
For use in a multimode optical fiber transmission system, a detector-equalizer including: an array of concentric, circular, photodetectors located at the end of said fiber, where each of said photodetectors is dimensioned to selectively intercept energy radiated from the end of said fiber by different groups of propagating modes; 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 10
Dependent Claim
81 words
For use in a multimode optical fiber transmission system, a detector-equalizer including: an array of concentric, circular, photodetectors located at the end of said fiber, where each of said photodetectors is dimensioned to selectively intercept energy radiated from the end of said fiber by different groups of propagating modes; 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 8 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
US3689772A
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 |