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US4076380A
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Graded index optical fiber
Assignee: AT&T Inc
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Filing: 1976-10-28
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Granted: 1978-02-28
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Expires: 1996-10-28
Abstract
Abstract A graded index optical fiber with a structure which results in improved pulse dispersion characteristics is disclosed. The refractive index properties of the fiber core may be defined in terms of coaxially nested tubular regions, each of different index of refraction, which together form a radially graded index of refraction. The optical properties of each tubular region vary periodically along the longitudinal direction. The longitudinal variation of each tubular region is in approximate antiphase with the longitudinal variation of the tubular regions immediately adjacent to it. In the disclosed structure each tubular region is composed of at least two intertwined helical ribbons of material.
Inventors
- 👤 Frank Vincent DiMarcello
- 👤 John Charles Williams
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 18:08
CPC Classifications
G; G02; G02B; G02B6/00; G02B6/02; G02B6/028; G02B6/0288; C; C03; C03B; C03B37/00; C03B37/01; C03B37/012; C03B37/014; C03B37/01413; C03B37/0142; C03B37/018; C03B37/01807; C03B37/01815; C03B2203/00; C03B2203/10; C03B2203/18; C03B2203/20; C03B2203/22; C03B2203/26; C03B2203/36; C03B2207/00; C03B2207/50; C03B2207/52; C03B2207/60; C03B2207/66; C03B2207/70; G02B6/02057; G02B6/02076; G02B6/0208; G02B6/02085; G02B2006/0209; G02B6/02214; G02B6/02285; G02B6/036; G02B6/03616; G02B6/03622; G02B6/03627
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
173 words
An optical fiber with a transmitting core, the refractive index properties of which are defined in terms of coaxially nested tubular regions which do not necessarily correspond with physically definable layers, comprising: a core with a cross section of nonuniform index of refraction, the tubular regions of which core comprise at least two aproximately continuous regions, each of which continuous regions has a different but approximately constant index of refraction and extends from one end of the fiber to the other end describing a helix whose axis is approximately collinear with the fiber axis, each of the tubular regions thereby having periodic longitudinal variations in index of refraction of period between 0.1 and 400 meters, the longitudinal variations in index of refraction of each tubular region being in approximate antiphase relation with the longitudinal variations in index of refraction of the tubular regions adjoining it, and the minimum index of refraction of each tubular region being approximately equal to the maximum index of refraction of the next adjacent tubular region of larger radius.
Claim 2
Dependent Claim
173 words
An optical fiber with a transmitting core, the refractive index properties of which are defined in terms of coaxially nested tubular regions which do not necessarily correspond with physically definable layers, comprising: a core with a cross section of nonuniform index of refraction, the tubular regions of which core comprise at least two aproximately continuous regions, each of which continuous regions has a different but approximately constant index of refraction and extends from one end of the fiber to the other end describing a helix whose axis is approximately collinear with the fiber axis, each of the tubular regions thereby having periodic longitudinal variations in index of refraction of period between 0.1 and 400 meters, the longitudinal variations in index of refraction of each tubular region being in approximate antiphase relation with the longitudinal variations in index of refraction of the tubular regions adjoining it, and the minimum index of refraction of each tubular region being approximately equal to the maximum index of refraction of the next adjacent tubular region of larger radius.
Claim 3
Dependent Claim
18 words
The device of claim 1 where the period of the longitudinal variation is between 1 and 100 meters.
Claim 4
Dependent Claim
29 words
The device of claim 1 wherein the index of refraction of the core is graded from a maximum at the core center to a minimum at its outside perimeter.
Claim 5
Dependent Claim
14 words
The device of claim 1 wherein the tubular regions are of approximately constant radius.
Claim 6
Dependent Claim
14 words
The device of claim 1 wherein the tubular regions correspond with physically definable layers.
References Cited (Backward Citations)
US3617917A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-02-27 | 1981-08-29 | 1982-02-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-02-27 | 1985-08-29 | 1986-02-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-02-27 | 1989-08-29 | 1990-02-28 | $7700.00 | Window Closed / Lapsed |