Patent US3832030A successfully refreshed from Google Patents.
US3832030A
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US
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Delay equalizers for multimode optical fibers
Assignee: AT&T Inc
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Filing: 1973-05-23
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Granted: 1974-08-27
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Expires: 1993-05-23
Abstract
Abstract The outputs of multimode optical fibers (i.e., fibers which support the simultaneous propagation of more than a single optical mode) suffer from signal distortion due to mode delay dispersion, that is, different modes travelling through the fibers at different forward velocities. In order to reduce this mode delay distortion in multimode optical fibers, a pair of back-to-back curvilinear conical lenses is located between two similar fibers. These lenses convert large angle modes to small angle modes, and vice versa; thereby the variation in the total delay of all modes propagating through the two fibers i.e., the mode delay dispersion, is reduced by these lenses.
Inventors
- 👤 D Gloge
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 13:50
CPC Classifications
G; G02; G02B; G02B6/00; G02B6/24; G02B6/26; G02B6/268; G02B5/00; G02B5/001; G02B6/10; G02B6/14; G02B6/264; H; H04; H04B; H04B10/00; H04B10/25; H04B10/2507; H04B10/2569; G02B6/28; G02B6/2804; G02B6/2861
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
116 words
A fiber optic mode delay equalization device which comprises a pair of optically refracting cone elements situated back to back and having a common axis of revolution for the refracting surfaces of the elements which is also in common with a common axis of a pair of optical fibers, each of said elements having a vertex on said common axis, the boundary of the cross-section of each element in any plane perpendicular to the axis being a circle, such that optical radiation ray emanating from one of the fibers at relatively small angles to the axis passes through the refracting elements and enters the other of the optical fibers at relatively large angles to the axis.
Claim 2
Dependent Claim
116 words
A fiber optic mode delay equalization device which comprises a pair of optically refracting cone elements situated back to back and having a common axis of revolution for the refracting surfaces of the elements which is also in common with a common axis of a pair of optical fibers, each of said elements having a vertex on said common axis, the boundary of the cross-section of each element in any plane perpendicular to the axis being a circle, such that optical radiation ray emanating from one of the fibers at relatively small angles to the axis passes through the refracting elements and enters the other of the optical fibers at relatively large angles to the axis.
Claim 3
Dependent Claim
26 words
The device recited in claim 1 in which each of the optical elements has a refracting surface in the form of substantially identical right circular cones.
Claim 4
Dependent Claim
37 words
The device recited in claim 2 in which the base surfaces of the cones are planar and which further includes a pair of substantially identical converging lenses having an optical axis along the common axis of revolution.
Claim 5
Dependent Claim
24 words
The device in claim 2 in which the base surfaces of the cones are spherical, thereby forming an optical lens between said base surfaces.
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) | 1977-08-26 | 1978-02-25 | 1978-08-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-08-26 | 1982-02-25 | 1982-08-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-08-26 | 1986-02-25 | 1986-08-27 | $7700.00 | Window Closed / Lapsed |