US4838643A
Expired / Lapsed
US
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Single mode bend insensitive fiber for use in fiber optic guidance applications
Assignee: Radio Frequency Systems Inc
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Filing: 1988-03-23
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Granted: 1989-06-13
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Expires: 2008-03-23
Abstract
Abstract A double-clad single mode optical fiber with a depressed inner cladding exhibits increased resistance to attenuation increases resulting from small radius bends and lower attenuation sensitivity to temperature changes when the mode field diameter is less than 7 um and the ratio of the radius of the inner cladding to the radius of the core is at least 6.5 to one.
Inventors
- 👤 Leslie B. Hodges
- 👤 Roger Charlton
- 👤 James H. Bowen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 08:13
CPC Classifications
G; G02; G02B; G02B6/00; G02B6/02; G02B6/036; G02B6/03616; G02B6/03622; G02B6/03627; G02B6/44; G02B6/4439; G02B6/4457
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
88 words
A single mode optical fiber, comprising: an inner core region having a refractive index n c and a maximum radius r c ; a first inner cladding surrounding said inner core region and having a refractive index n 1 and a maximum radius r 1 ; and a second outer cladding surrounding said first inner cladding having a refractive index n 2 , wherein the refractive indices have the following relationship:n 1 <n 2 <n c and the ratio r 1 :4 c is not less than 6.5:1.0.
Claim 2
Dependent Claim
88 words
A single mode optical fiber, comprising: an inner core region having a refractive index n c and a maximum radius r c ; a first inner cladding surrounding said inner core region and having a refractive index n 1 and a maximum radius r 1 ; and a second outer cladding surrounding said first inner cladding having a refractive index n 2 , wherein the refractive indices have the following relationship:n 1 <n 2 <n c and the ratio r 1 :4 c is not less than 6.5:1.0.
Claim 3
Dependent Claim
21 words
A single mode fiber, as described in claim 1, wherein the ratio r 1 :r c is not less than 8:1.
Claim 4
Dependent Claim
80 words
A single mode fiber, as described in claim 2, wherein the difference Δ+ between the refractive indices of the core region n c and that of the outer cladding n 2 is given by ##EQU3## and said difference lies within the range of 0.75 to 0.95 and the difference Δ- between the refractive indices of the first cladding n 1 and the second outer cladding n 2 is given by ##EQU4## and lies in the range of 0.04 to 0.06.
Claim 5
Dependent Claim
55 words
A single mode optical fiber, as described in claim 3, wherein the optical fiber exhibits a mode field diameter as defined by EIA method-RS455-174 lying in the range of 5.0 um to 7.0 um and has a cutoff wavelength as defined by EIA method RS455-80 lying in the range of 1130 nm to 1330 nm.
Claim 6
Dependent Claim
39 words
A single mode optical fiber, as described in claim 4, wherein the mode field diameter lies in the range of 6.0 um to 6.5 um and the cutoff wavelength lies in the range of 1200 nm to 1280 nm.
Claim 7
Dependent Claim
34 words
A single mode optical fiber, as described in claim 1, wherein the mode field diameter as defined by EIA method RS455-174 of said fiber lies in the range of 5.0 um to 7.0 um.
Claim 8
Dependent Claim
25 words
A single mode optical fiber, as described in claim 6, wherein the mode field diameter lies within the range of 6.0 um to 6.5 um.
Claim 9
Dependent Claim
22 words
A single mode optical fiber, as described in claim 7, wherein the ratio r 1 :r c is not less than 8:1.
Claim 10
Dependent Claim
22 words
A single mode optical fiber, as described in claim 6, wherein the ratio r 1 :r c is not less than 8:1.
Claim 11
Dependent Claim
136 words
An optical fiber assembly, for use in optical fiber guidance systems, comprising: means for storing optical fiber in a wound condition, said means including means for deploying said fiber in an axial direction from said storing means; and a single mode optical fiber wound and stored in said storing means, said fiber comprising, an inner core region having a refractive index n c and a maximum radius r c , a first inner cladding surrounding said inner core region and having a refractive index n l and a maximum radius r l , and a second outer cladding surrounding said first inner cladding having a refractive index n 2 , wherein the refractive indices have the following relationship: n 1 <n 2 <n c and the ratio r l :r c is not less than 6.5:1.0.
Claim 12
Dependent Claim
136 words
An optical fiber assembly, for use in optical fiber guidance systems, comprising: means for storing optical fiber in a wound condition, said means including means for deploying said fiber in an axial direction from said storing means; and a single mode optical fiber wound and stored in said storing means, said fiber comprising, an inner core region having a refractive index n c and a maximum radius r c , a first inner cladding surrounding said inner core region and having a refractive index n l and a maximum radius r l , and a second outer cladding surrounding said first inner cladding having a refractive index n 2 , wherein the refractive indices have the following relationship: n 1 <n 2 <n c and the ratio r l :r c is not less than 6.5:1.0.
Claim 13
Dependent Claim
21 words
An optical fiber assembly, as described in claim 10, wherein the ratio r 1 :r c is not less than 8:1.
Claim 14
Dependent Claim
80 words
An optical fiber assembly, as described in claim 11, wherein the difference Δ+ between the refractive indices of the core region n c and that of the outer cladding n 2 is given by ##EQU5## and said difference lies within the range of 0.75 to 0.95 and the difference Δ- between the refractive indices of the first cladding n 1 and the second outer cladding n 2 is given by ##EQU6## and lies in the range of 0.04 to 0.06.
Claim 15
Dependent Claim
55 words
An optical fiber assembly, as described in claim 12, wherein the optical fiber exhibits a mode field diameter as defined by EIA method RS455-174 lying in the range of 5.0 um to 7.0 um and has a cutoff wavelength as defined by EIA method RS455-80 lying in the range of 1130 nm to 1330 nm.
Claim 16
Dependent Claim
38 words
A optical fiber assembly, as described in claim 13, wherein the mode field diameter lies in the range of 6.0 um to 6.5 um and the cutoff wavelength lies in the range of 1200 nm to 1280 nm.
Claim 17
Dependent Claim
33 words
An optical fiber assembly, as described in claim 10, wherein the mode field diameter as defined by EIA method RS455-174 of said fiber lies in the range of 5.0 um to 7.0 um.
Claim 18
Dependent Claim
24 words
An optical fiber assembly, as described in claim 15, wherein the mode field diameter lies within the range of 6.0 um to 6.5 um.
Claim 19
Dependent Claim
21 words
An optical fiber assembly, as described in claim 16, wherein the ratio r 1 :r c is not less than 8:1.
Claim 20
Dependent Claim
21 words
An optical fiber assembly, as described in claim 15, wherein the ratio r 1 :r c is not less than 8:1.
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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) | 1992-06-12 | 1992-12-12 | 1993-06-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-06-12 | 1996-12-12 | 1997-06-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-06-12 | 2000-12-12 | 2001-06-13 | $7700.00 | Window Closed / Lapsed |