Patent US1976423A successfully refreshed from Google Patents.
Patent US4205901A successfully refreshed from Google Patents.
US4205901A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Limited mode optical fiber
Assignee: International Standard Electric Corp
•
Filing: 1978-10-04
•
Granted: 1980-06-03
•
Expires: 1998-10-04
Abstract
Abstract A single mode optical fiber having a central core region of uniform composition and thickness and core end regions each having a core with a graded composition and increasing thickness towards the ends of the fiber. The fiber maintains a constant normalized frequency with a minimum bending loss. Methods are also provided for forming the fibers from a fiber optic preform.
Inventors
- 👤 Melvin M. Ramsay
- 👤 Philip W. Black
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 12:53
CPC Classifications
G; G02; G02B; G02B6/00; G02B6/24; G02B6/255; G02B6/2552; C; C03; C03B; C03B37/00; C03B37/01; C03B37/012; C03B37/014; C03B37/018; G02B6/26; G02B6/262; C03B2203/00; C03B2203/10; C03B2203/18; C03B2203/22; C03B2203/24; C03B2203/26
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
57 words
A limited mode optical fiber comprising: a cladding layer; and a core having a central region of constant material composition and thickness and graded core end regions at both ends of said central region, said end regions having axially varying composition and thickness to provide a substantially constant normalized frequency throughout the length of the optical fiber.
Claim 2
Dependent Claim
57 words
A limited mode optical fiber comprising: a cladding layer; and a core having a central region of constant material composition and thickness and graded core end regions at both ends of said central region, said end regions having axially varying composition and thickness to provide a substantially constant normalized frequency throughout the length of the optical fiber.
Claim 3
Dependent Claim
53 words
A limited mode optical fiber as described in claim 1 wherein the thickness of the core end regions increases as the ends of the optical fiber are approached, and the composition of the core end regions is changed along the length of the core end regions in accordance with the increased thickness thereof.
Claim 4
Dependent Claim
125 words
A limited mode optical fiber, comprising: a cladding layer; and a core having a central region of constant material composition and thickness and graded core end regions at both ends of said central region, the thickness of the core end regions increasing as the ends of the optical fiber are approached, and the composition of the core end regions being changed along the length of the core end regions so that the refractive index of the graded core end regions decreases along the lengths of the graded core end regions as the ends of the optical fiber are approached in accordance with the increased thickness of said core end regions, whereby a substantially constant normalized frequency is maintained throughout the length of the optical fiber.
Claim 5
Dependent Claim
125 words
A limited mode optical fiber, comprising: a cladding layer; and a core having a central region of constant material composition and thickness and graded core end regions at both ends of said central region, the thickness of the core end regions increasing as the ends of the optical fiber are approached, and the composition of the core end regions being changed along the length of the core end regions so that the refractive index of the graded core end regions decreases along the lengths of the graded core end regions as the ends of the optical fiber are approached in accordance with the increased thickness of said core end regions, whereby a substantially constant normalized frequency is maintained throughout the length of the optical fiber.
Claim 6
Dependent Claim
76 words
A limited mode optical fiber, comprising: a cladding layer; and a core having a central region of constant material composition and thickness and graded core end regions at both ends of said central region, said end regions having axially varying composition and thickness to provide a normalized frequency of the optical fiber held within limits which provide the central core region and the graded core end regions with the same set of bound non-radiating frequency modes.
Claim 7
Dependent Claim
76 words
A limited mode optical fiber, comprising: a cladding layer; and a core having a central region of constant material composition and thickness and graded core end regions at both ends of said central region, said end regions having axially varying composition and thickness to provide a normalized frequency of the optical fiber held within limits which provide the central core region and the graded core end regions with the same set of bound non-radiating frequency modes.
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) | 1983-06-03 | 1983-12-03 | 1984-06-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-06-03 | 1987-12-03 | 1988-06-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-06-03 | 1991-12-03 | 1992-06-03 | $7700.00 | Window Closed / Lapsed |