US4770494A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Low-loss silica optical waveguides
Assignee: Nokia Bell Labs
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Filing: 1986-02-12
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Granted: 1988-09-13
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Expires: 2006-02-12
Abstract
Abstract Certain dopant materials, when present in a significant power-carrying portion of a silica-based optical waveguide fiber, are effective as intrinsic loss-reducing agents; the concentration of such dopant materials is at significantly lower levels as compared with levels used for producing a refractive index difference. Suitable in this respect are germania and phosphorus pentoxide as added to essentially pure silica or to silica containing other dopant additives such as, e.g., alumina or fluorine as may be used in a waveguiding core-cladding structure. Intrinsic loss in the vicinity of 0.2 dB/km is readily realized.
Inventors
- 👤 Roseann Csencsits
- 👤 Paul J. Lemaire
- 👤 Katherine T. Nelson
- 👤 Kenneth L. Walker
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 17:12
CPC Classifications
G; G02; G02B; G02B6/00; G02B6/44; G02B6/4401; G02B6/4402; C; C03; C03C; C03C13/00; C03C13/04; C03C13/045; G02B6/02
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
169 words
Silica-based optical fiber waveguide comprising a glass core region and a glass cladding region which surrounds said glass core region and which has a refractive index which is lower than the refractive index of said glass core region, a significant power-carrying region of said fiber waveguide here being defined such that, when optical radiation travels in said waveguide, at least 98 percent of the power of said radiation travels in said significant power-carrying region, said waveguide being characterized in that said significant power-carrying region comprises at least one dopant selected from the group consisting of germania and phosphorus pentoxide, said at least one dopant being present in said significant power-carrying region in an amount which is sufficiently small so as not to significantly contribute to waveguiding, said at least one dopant being present in said significant power-carrying region in an amount which is greater than or equal to 0.02 mole percent, and said waveguide having intrinsic loss which is less than 0.25 dB/km at a wavelength of 1.57 micrometers.
Claim 2
Dependent Claim
169 words
Silica-based optical fiber waveguide comprising a glass core region and a glass cladding region which surrounds said glass core region and which has a refractive index which is lower than the refractive index of said glass core region, a significant power-carrying region of said fiber waveguide here being defined such that, when optical radiation travels in said waveguide, at least 98 percent of the power of said radiation travels in said significant power-carrying region, said waveguide being characterized in that said significant power-carrying region comprises at least one dopant selected from the group consisting of germania and phosphorus pentoxide, said at least one dopant being present in said significant power-carrying region in an amount which is sufficiently small so as not to significantly contribute to waveguiding, said at least one dopant being present in said significant power-carrying region in an amount which is greater than or equal to 0.02 mole percent, and said waveguide having intrinsic loss which is less than 0.25 dB/km at a wavelength of 1.57 micrometers.
Claim 3
Dependent Claim
20 words
Waveguide of claim 1 in which said glass regions comprise silica in an amount of at least 90 mole percent.
Claim 4
Dependent Claim
27 words
Waveguide of claim 1 in which said dopant contributes less than 40 percent to the relative refractive index difference between said core region and said cladding region.
Claim 5
Dependent Claim
15 words
Waveguide of claim 1 in which waveguiding is effected primarily by doping said cladding region.
Claim 6
Dependent Claim
15 words
Waveguide of claim 1 in which said cladding region comprises fluorine as an index-decreasing dopant.
Claim 7
Dependent Claim
15 words
Waveguide of claim 1 in which waveguiding is effected primarily by doping said core region.
Claim 8
Dependent Claim
15 words
Waveguide of claim 1 in which said core region comprises alumina as an index-increasing dopant.
Claim 9
Dependent Claim
10 words
Waveguide of claim 1 in which said dopant is germania.
Claim 10
Dependent Claim
11 words
Waveguide of claim 1 in which said dopant is phosphorus pentoxide.
Claim 11
Dependent Claim
21 words
Waveguide of claim 1 in which said dopant is germania in said core region and phosphorus pentoxide in said cladding region.
Claim 12
Dependent Claim
12 words
Waveguide of claim 1, said waveguide being designed for essentially single-mode transmission.
Claim 13
Dependent Claim
11 words
Waveguide of claim 1, said waveguide being designed for multi-mode transmission.
Claim 14
Dependent Claim
20 words
Waveguide of claim 1, said dopant being present in said glass in an amount of less than 1.5 mole percent.
Claim 15
Dependent Claim
191 words
Silica-based optical fiber waveguide comprising a glass core region and a glass cladding region which surrounds said glass core region and which has a refractive index which is lower than the refractive index of said glass core region, a significant power-carrying region of said fiber waveguide here being defined such that, when optical radiation travels in said waveguide, at least 98 percent of the power of said radiation travels in said significant power-carrying region, said waveguide being characterized in that said significant power-carrying region comprises at least one dopant oxide which is such that, at a temperature which is greater than 1900 degrees C., there exists a stable suboxide of the cation of said at least one dopant oxide, said at least one dopant oxide being present in said significant power-carrying region in an amount which is sufficiently small so as not to significantly contribute to waveguiding, said at least one dopant oxide being present in said significant power-carrying region in an amount which is greater than or equal to 0.02 mole percent, and said waveguide having intrinsic loss which is less than 0.25 dB/km at a wavelength of 1.57 micrometers.
Claim 16
Dependent Claim
191 words
Silica-based optical fiber waveguide comprising a glass core region and a glass cladding region which surrounds said glass core region and which has a refractive index which is lower than the refractive index of said glass core region, a significant power-carrying region of said fiber waveguide here being defined such that, when optical radiation travels in said waveguide, at least 98 percent of the power of said radiation travels in said significant power-carrying region, said waveguide being characterized in that said significant power-carrying region comprises at least one dopant oxide which is such that, at a temperature which is greater than 1900 degrees C., there exists a stable suboxide of the cation of said at least one dopant oxide, said at least one dopant oxide being present in said significant power-carrying region in an amount which is sufficiently small so as not to significantly contribute to waveguiding, said at least one dopant oxide being present in said significant power-carrying region in an amount which is greater than or equal to 0.02 mole percent, and said waveguide having intrinsic loss which is less than 0.25 dB/km at a wavelength of 1.57 micrometers.
Claim 17
Dependent Claim
22 words
Waveguide of claim 14 made from a preform whose manufacture involves processing at a temperature which is greater than 1900 degrees C.
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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) | 1991-09-13 | 1992-03-14 | 1992-09-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-09-13 | 1996-03-14 | 1996-09-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-09-13 | 2000-03-14 | 2000-09-13 | $7700.00 | Window Closed / Lapsed |