Patent US4439007A successfully refreshed from Google Patents.
US4439007A
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Low dispersion single mode fiber
Assignee: Furukawa Electric North America Inc
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Filing: 1981-06-09
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Granted: 1984-03-27
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Expires: 2001-06-09
Abstract
Abstract A low-loss single mode fiber with low total dispersion within the wavelength range 1.25-1.385 μm and low added cabling loss is disclosed. The fiber has relatively high Δ to assure low cabling loss. The high Δ is obtained, however, without paying a cost in high material dispersion by providing at least 20 percent of the Δ by down-doping of the fiber cladding.
Inventors
- 👤 Paul D. Lazay
- 👤 Paul J. Lemaire
- 👤 Arthur D. Pearson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 14:10
CPC Classifications
G; G02; G02B; G02B6/00; G02B6/02; G02B6/036; G02B6/03616; G02B6/03622; G02B6/03627; G02B6/02214
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
79 words
A single mode fiber comprising (a) an up-doped core of diameter less than 9 μm, (b) a down-doped cladding with no abrupt change in index of refraction, and which contributes at least 20 percent of the fiber Δ, the Δ of the fiber being greater than 0.3 percent and less than 0.75 percent, the dispersion of the fiber being less than 5 psec/nm-km within the wavelength range of 1.25-1.385 μm, and the cutoff wavelength being less than 1.31 μm.
Claim 2
Dependent Claim
79 words
A single mode fiber comprising (a) an up-doped core of diameter less than 9 μm, (b) a down-doped cladding with no abrupt change in index of refraction, and which contributes at least 20 percent of the fiber Δ, the Δ of the fiber being greater than 0.3 percent and less than 0.75 percent, the dispersion of the fiber being less than 5 psec/nm-km within the wavelength range of 1.25-1.385 μm, and the cutoff wavelength being less than 1.31 μm.
Claim 3
Dependent Claim
15 words
The fiber of claim 1 wherein the fiber material is at least 90 percent silica.
Claim 4
Dependent Claim
18 words
The fiber of claim 2 wherein the core of the fiber comprises less than 5 mole percent germania.
Claim 5
Dependent Claim
18 words
The fiber of claim 3 wherein the cladding of the fiber comprises greater than 0.5 mole percent fluorine.
Claim 6
Dependent Claim
11 words
The fiber of claim 4 wherein the fiber further comprises phosphorus.
Claim 7
Dependent Claim
17 words
The fiber of claim 5 wherein the down-doped cladding to core diameter ratio is greater than 2.
Claim 8
Dependent Claim
15 words
The fiber of claim 6 wherein at least part of the index configuration is graded.
Claim 9
Dependent Claim
20 words
The fiber of claim 7 wherein the outer regions of the fiber may be attributed to a doped substrate tube.
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) | 1987-03-27 | 1987-09-26 | 1988-03-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-03-27 | 1991-09-26 | 1992-03-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-03-27 | 1995-09-26 | 1996-03-27 | $7700.00 | Window Closed / Lapsed |