Patent US3823997A successfully refreshed from Google Patents.
US3823997A
Expired / Lapsed
US
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Graded-index optical fiber
Assignee: AT&T Inc
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Filing: 1973-06-18
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Granted: 1974-07-16
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Expires: 1993-06-18
Abstract
Abstract It is shown that minimum delay distortion is realized in a graded-index multimode optical fiber comprising an inner core of radius a surrounded by a suitable cladding when the refractive index n(r), at any radius r less than a, is given by
Inventors
- 👤 D Gloge
- 👤 R Bank
- 👤 E Marcatili
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 17:51
CPC Classifications
G; G02; G02B; G02B6/00; G02B6/02; G02B6/028; G02B6/0288
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
79 words
An optical fiber comprising: an inner core region surrounded by an outer cladding; characterized in that the refractive index n(r) of said core region varies as a function of the radial distance r from the center of said core substantially as n(r) no (1 - 2 Delta (r/a)2-2 )1/2, where a is the radius of said core; no is the refractive index at the center of said core; nc is the refractive index of said core at r a.
Claim 2
Dependent Claim
79 words
An optical fiber comprising: an inner core region surrounded by an outer cladding; characterized in that the refractive index n(r) of said core region varies as a function of the radial distance r from the center of said core substantially as n(r) no (1 - 2 Delta (r/a)2-2 )1/2, where a is the radius of said core; no is the refractive index at the center of said core; nc is the refractive index of said core at r a.
Claim 3
Dependent Claim
17 words
The fiber according to claim 1 wherein said cladding is a low-loss material of refractive index nc.
Claim 4
Dependent Claim
13 words
The fiber according to claim 1 where said cladding is a lossy jacket.
Claim 5
Dependent Claim
23 words
The fiber according to claim 1 wherein said cladding is a low-loss jacket of refractive index n, where nc < n < no.
Claim 6
Dependent Claim
31 words
The fiber according to claim 1 wherein said cladding includes an intermediate jacket of low-loss material having a refractive index less than nc, surrounded by an outer, lossy layer of material.
Claim 7
Dependent Claim
12 words
The fiber according to claim 1 wherein Delta < or = 0.033.
Claim 8
Dependent Claim
89 words
An optical fiber comprising: an inner core region having a semicircular cross-section surrounded by an outer cladding; characterized in that the refractive index n(r) of said core region varies as a function of the radial distance r from the center of the planar surface of said core substantially as n(r) no (1 - 2 Delta (r/a)2-2 )1/2 where a is the radius of said core; no is the refractive index at the center of said planar surface; and nc is the refractive index of said core at r a.
Claim 9
Dependent Claim
89 words
An optical fiber comprising: an inner core region having a semicircular cross-section surrounded by an outer cladding; characterized in that the refractive index n(r) of said core region varies as a function of the radial distance r from the center of the planar surface of said core substantially as n(r) no (1 - 2 Delta (r/a)2-2 )1/2 where a is the radius of said core; no is the refractive index at the center of said planar surface; and nc is the refractive index of said core at r a.
Claim 10
Dependent Claim
17 words
The fiber according to claim 7 wherein said cladding is a low-loss material of refractive index nc.
Claim 11
Dependent Claim
22 words
The fiber according to claim 7 wherein the cladding along the planar surface of said core region includes a metallized reflecting surface.
References Cited (Backward Citations)
US3614197A
Cited
US3785718A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-07-15 | 1978-01-14 | 1978-07-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-07-15 | 1982-01-14 | 1982-07-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-07-15 | 1986-01-14 | 1986-07-16 | $7700.00 | Window Closed / Lapsed |