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US4560247A
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Large bandwidth optical fibers
Assignee: Saint Gobain Quartz SAS
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Filing: 1983-07-01
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Granted: 1985-12-24
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Expires: 2003-07-01
Abstract
Abstract Multimode optical fibers are described comprising a cylindrical core with a radius a o exhibiting an index of refraction n o surrounded by a cladding having an outer radius a in which the index of refraction varies continually from the core to the periphery from a value of n 1 to a lower value n e . Between the core and cladding there is a step change Δn in their respective indices of refraction whose value is a function of the ratio a o /a. Such fibers have both slight attenuation and slight dispersion and can be manufactured using processes similar to those used in making step-index optical fibers.
Inventors
- 👤 Pierre Aldebert
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 14:05
CPC Classifications
G; G02; G02B; G02B6/00; G02B6/02; G02B6/028; G02B6/0288; G02B6/0283; G02B6/0285
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
149 words
An optical fiber comprising a core of silica glass with radius a o and constant index of refraction n o surrounded by a doped silica glass cladding with outer radius a, in which the index of refraction varies continuously from a value n 1 at an interface between the core and the cladding to a value n e at the periphery of the cladding n e being less than n 1 and n 1 being less than n o wherein there is a step change in the index of refraction at the interface between the core and the cladding and a measure of this step change, E o= (n o 2 -n 1 2 )/(n o 2 -n e 2 ), is related to the ratio a o /a in accordance with the following relation: ##EQU3## where x o =a o /a and x o is less than 0.83.
Claim 2
Dependent Claim
149 words
An optical fiber comprising a core of silica glass with radius a o and constant index of refraction n o surrounded by a doped silica glass cladding with outer radius a, in which the index of refraction varies continuously from a value n 1 at an interface between the core and the cladding to a value n e at the periphery of the cladding n e being less than n 1 and n 1 being less than n o wherein there is a step change in the index of refraction at the interface between the core and the cladding and a measure of this step change, E o= (n o 2 -n 1 2 )/(n o 2 -n e 2 ), is related to the ratio a o /a in accordance with the following relation: ##EQU3## where x o =a o /a and x o is less than 0.83.
Claim 3
Dependent Claim
40 words
The optical fiber of claim 1 wherein the index of refraction, n, in the cladding varies with radial distance, r, in the cladding in accordance with the following relation: ##EQU4## where x=r/a and U=(n.sub.o.sup.2 -n.sup.2)/(n.sub.o.sup.2 -n.sub.e.sup.2) E.sub.o =(n.sub.o.sup.2 -n.sub.1.sup.2)/(n.sub.o.sup.2 -n.sub.e.sup.2).
Claim 4
Dependent Claim
16 words
The optical fiber of claim 1 wherein a o /a is between about 0.3 and 0.7.
Claim 5
Dependent Claim
15 words
The optical fiber of claim 1 wherein the cladding is a fluorine doped silica glass.
Claim 6
Dependent Claim
15 words
The optical fiber of claim 1 where in the core is a doped silica glass.
Claim 7
Dependent Claim
24 words
The optical fiber of claim 1 where in the core is a doped silica glass and the cladding is a fluorine doped silica glass.
Claim 8
Dependent Claim
130 words
An optical fiber comprising a core of silica glass with radius a o and constant index of refraction n o surrounded by a doped silica glass cladding with outer radius a, wherein there is a step change in the index of refraction at an interface between the core and the cladding and in which the index of refraction, n, in the cladding varies continuously with radial distance, r, in the cladding from a value n 1 at the interface between the core and the cladding to a value n e at the periphery of the cladding, n e being less than n 1 and n 1 being less than n o , in accordance with the following relation: ##EQU5## where x=r/a and U=(n.sub.o.sup.2 -n.sup.2)/(n.sub.o.sup.2 -n.sub.e.sup.2), and E.sub.o =(n.sub.o.sup.2 -n.sub.1.sup.2)/(n.sub.o.sup.2 -n.sub.e.sup.2).
Claim 9
Dependent Claim
130 words
An optical fiber comprising a core of silica glass with radius a o and constant index of refraction n o surrounded by a doped silica glass cladding with outer radius a, wherein there is a step change in the index of refraction at an interface between the core and the cladding and in which the index of refraction, n, in the cladding varies continuously with radial distance, r, in the cladding from a value n 1 at the interface between the core and the cladding to a value n e at the periphery of the cladding, n e being less than n 1 and n 1 being less than n o , in accordance with the following relation: ##EQU5## where x=r/a and U=(n.sub.o.sup.2 -n.sup.2)/(n.sub.o.sup.2 -n.sub.e.sup.2), and E.sub.o =(n.sub.o.sup.2 -n.sub.1.sup.2)/(n.sub.o.sup.2 -n.sub.e.sup.2).
Claim 10
Dependent Claim
16 words
The optical fiber of claim 7 wherein a o /a is between about 0.3 and 0.7.
Claim 11
Dependent Claim
15 words
The optical fiber of claim 7 wherein the cladding is a fluorine doped silica glass.
Claim 12
Dependent Claim
15 words
The optical fiber of claim 7 where in the core is a doped silica glass.
Claim 13
Dependent Claim
24 words
The optical fiber of claim 7 where in the core is a doped silica glass and the cladding is a fluorine doped silica glass.
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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) | 1988-12-23 | 1989-06-24 | 1989-12-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-12-23 | 1993-06-24 | 1993-12-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-12-23 | 1997-06-24 | 1997-12-24 | $7700.00 | Window Closed / Lapsed |