Patent US4412722A successfully refreshed from Google Patents.
US4412722A
Expired / Lapsed
US
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Single mode fiber with graded index of refraction
Assignee: AT&T Inc
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Filing: 1981-10-26
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Granted: 1983-11-01
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Expires: 2001-10-26
Abstract
Abstract This invention involves optical fiber which supports essentially only a single guided mode, perhaps degenerate, at the transmission wavelength, usually between 0.6 and 1.7 microns. The index of refraction of the core material is graded in the radial direction so as to yield an optical fiber with very low total dispersion and therefore high bandwidth. Specific embodiments include, in addition to the low dispersion characteristic, improved field confinement, and therefore permit lower clad-to-core ratios then heretofore believed practical. Additional advantages which accrue as a result of the greater field confinement include lower cabling, microbending, and curvature-induced losses.
Inventors
- 👤 Anthony Carnevale
- 👤 Un-Chul Paek
- 👤 George E. Peterson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 19:34
CPC Classifications
G; G02; G02B; G02B6/00; G02B6/02; G02B6/028; G02B6/0281; G02B6/02214; G02B6/02219; G02B6/02228; G02B6/02238
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
121 words
An optical fiber comprising a core with a graded index of refraction given substantially by a profile exponent α≦2 and a cladding, the Δ index of refraction of the core, core radius, and profile exponent α of the core being such that (a) the fiber supports essentially only one propagating mode in the wavelength range of 0.6-1.7 microns; (b) the fiber has a total dispersion <5 psec/Km.nm in at least a part of the spectral region from 0.6-1.7 microns; (c) the total dispersion associated with the fiber is the sum of at least a nonzero waveguide dispersion and a nonzero material dispersion; and (d) the wavelength at which the total dispersion is minimized is different than the zero material dispersion wavelength.
Claim 2
Dependent Claim
121 words
An optical fiber comprising a core with a graded index of refraction given substantially by a profile exponent α≦2 and a cladding, the Δ index of refraction of the core, core radius, and profile exponent α of the core being such that (a) the fiber supports essentially only one propagating mode in the wavelength range of 0.6-1.7 microns; (b) the fiber has a total dispersion <5 psec/Km.nm in at least a part of the spectral region from 0.6-1.7 microns; (c) the total dispersion associated with the fiber is the sum of at least a nonzero waveguide dispersion and a nonzero material dispersion; and (d) the wavelength at which the total dispersion is minimized is different than the zero material dispersion wavelength.
Claim 3
Dependent Claim
7 words
The fiber of claim 1 where α<2.
Claim 4
Dependent Claim
7 words
The fiber of claim 2 where α<1.8.
Claim 5
Dependent Claim
9 words
The fiber of claim 3 where α is 1.0±0.2.
Claim 6
Dependent Claim
17 words
The fiber of any of claims 1 through 4 where the clad-to-core ratio is less than 10.
Claim 7
Dependent Claim
13 words
The fiber of claim 5 where the clad-to-core ratio is less than 9.3.
Claim 8
Dependent Claim
13 words
The fiber of claim 5 where the clad-to-core ratio is less than 9.
Claim 9
Dependent Claim
13 words
The fiber of claim 5 where the clad-to-core ratio is less than 8.
Claim 10
Dependent Claim
21 words
The fiber of claim 5 where the cladding comprises two regions with different characteristics indices of refraction, profile exponents or both.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-10-31 | 1987-05-02 | 1987-11-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-10-31 | 1991-05-02 | 1991-11-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-10-31 | 1995-05-02 | 1995-11-01 | $7700.00 | Window Closed / Lapsed |