Patent US4435040A successfully refreshed from Google Patents.
US4435040A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Double-clad optical fiberguide
Assignee: AT&T Inc
•
Filing: 1981-09-03
•
Granted: 1984-03-06
•
Expires: 2001-09-03
Abstract
Abstract The invention pertains to W-profile single-mode silica-based optical fiberguide, and to communication systems employing these fiberguide. Such guides can be designed to have large bandwidth over a wide wavelength region, and, in particular, to have minimal chromatic dispersion at two different wavelengths, e.g., about 1.3 μm and about 1.55 μm, the wavelengths of loss minima in silica. Disclosed are ranges of fiber parameters that can yield these and other advantageous fiberguide characteristics. In particular, in fibers according to the invention the difference between core and outer cladding refractive index is between about 0.1% and 0.4% of the outer cladding index, the difference between the inner cladding and the outer cladding index is between about 1 times and about 3 times the difference between core and outer cladding, the core radius is between about 0.5 and 0.8 times the outer radius of the inner cladding, and the outer radius of the inner cladding is at least about 5 μm. Any suitable dopant, e.g., fluorine, germanium, boron or phosphorus, can be used. In preferred embodiments, the core is undoped SiO 2 , or lightly Ge-doped SiO 2 , and the two clads are fluorine-doped.
Inventors
- 👤 Leonard G. Cohen
- 👤 Wanda L. Mammel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 23:14
CPC Classifications
G; G02; G02B; G02B6/00; G02B6/02; G02B6/02214; G02B6/02219; G02B6/02223; C; C03; C03C; C03C13/00; C03C13/04; C03C13/045; G02B6/036; G02B6/03616; G02B6/03622; G02B6/03627; G02B6/03638; G02B6/03644; G02B6/03655; G02B6/03605; G02B6/03611
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
191 words
An optical communication system comprising a light source and a detector, further comprising silica-based single-mode optical fiberguide comprising (a) a core region having an effective radius and a first effective refractive index, (b) an inner cladding region concentrically surrounding the core, the inner cladding having an effective outer radius and a second effective refractive index, and (c) an outer cladding region concentrically surrounding the inner cladding, having an effective thickness and a third effective refractive index, CHARACTERIZED IN THAT (d) the difference between the first and the third index is between about 0.1% and about 0.4% of the value of the third index, with the first index being larger than the third index, (e) the difference between the third and the second index is between about 1 times and about 3 times the difference between the first and the third index, with the third index being larger than the second index, (f) the effective core radius is between about 0.5 times and about 0.8 times the effective outer radius of the inner cladding region, and (g) the effective outer radius of the inner cladding region is at least about 5 μm.
Claim 2
Dependent Claim
191 words
An optical communication system comprising a light source and a detector, further comprising silica-based single-mode optical fiberguide comprising (a) a core region having an effective radius and a first effective refractive index, (b) an inner cladding region concentrically surrounding the core, the inner cladding having an effective outer radius and a second effective refractive index, and (c) an outer cladding region concentrically surrounding the inner cladding, having an effective thickness and a third effective refractive index, CHARACTERIZED IN THAT (d) the difference between the first and the third index is between about 0.1% and about 0.4% of the value of the third index, with the first index being larger than the third index, (e) the difference between the third and the second index is between about 1 times and about 3 times the difference between the first and the third index, with the third index being larger than the second index, (f) the effective core radius is between about 0.5 times and about 0.8 times the effective outer radius of the inner cladding region, and (g) the effective outer radius of the inner cladding region is at least about 5 μm.
Claim 3
Dependent Claim
25 words
System of claim 1 wherein the refractive index of the core region is substantially constant over more than about 90% of the core cross section.
Claim 4
Dependent Claim
18 words
System of claims 1 or 2, wherein at least the inner cladding region of the fiberguide contains fluorine.
Claim 5
Dependent Claim
14 words
System of claim 3, wherein the outer cladding region of the fiberguide contains fluorine.
Claim 6
Dependent Claim
13 words
System of claim 4, wherein the core consists essentially of SiO 2 .
Claim 7
Dependent Claim
17 words
System of claims 1 or 2, wherein at least the core region of the fiberguide contains germania.
Claim 8
Dependent Claim
19 words
System of claims 1 or 2, wherein at least one of the cladding regions of the fiberguide contains phosphorus.
Claim 9
Dependent Claim
24 words
System of claims 1 or 2, wherein the effective thickness of the outer cladding region is at least about 6 times the core radius.
Claim 10
Dependent Claim
17 words
System of claims 1 or 2, wherein the effective core radius is at least about 4 μm.
Claim 11
Dependent Claim
32 words
System of claims 1 or 2, wherein the difference between the first and the third effective index is between about 0.15% and about 0.3% of the value of the third effective index.
Claim 12
Dependent Claim
34 words
System of claim 10, wherein the difference between the third and the second effective index is between about 1.5 times and about 2.5 times the difference between the first and the third effective index.
Claim 13
Dependent Claim
136 words
System according to claims 1 or 2, wherein (h) core region has a radius of at least about 4 μm. (i) the inner cladding region has an outer radius greater than about 5 μm, (j) the outer cladding region has a thickness at least about 8 times the core radius, (k) the difference between the first and the third effective index is between about 0.15% and about 0.3% of the value of the third effective index, (l) the difference between the third and the second effective index is between about 1.5 times and about 2.5 times the difference between the first and the third effective index, (m) the core radius is between about 0.5 times and about 0.8 times the outer radius of the inner cladding, and (n) the core consists essentially of SiO 2 .
Claim 14
Dependent Claim
15 words
System of claim 12, wherein the inner and the outer cladding comprise fluorine doped silica.
Claim 15
Dependent Claim
176 words
Silica-based single-mode optical fiberguide comprising (a) a core region having an effective radius and a first effective refractive index, (b) an inner cladding region concentrically surrounding the core, the inner cladding having an effective outer radius and a second effective refractive index, and (c) an outer cladding region concentrically surrounding the inner cladding having an effective thickness and a third effective refractive index, CHARACTERIZED IN THAT (d) the difference between the first and the third index is between about 0.1% and about 0.4% of the value of the third index, with the first index being larger than the third index, (e) the difference between the third and the second index is between about 1 times and about 3 times the difference between the first and the third index, with the third index being larger than the second index, (f) the effective core radius is between about 0.5 times and about 0.8 times the effective outer radius of the inner cladding, and (g) the effective outer radius of the inner cladding is at least about 5 μm.
Claim 16
Dependent Claim
176 words
Silica-based single-mode optical fiberguide comprising (a) a core region having an effective radius and a first effective refractive index, (b) an inner cladding region concentrically surrounding the core, the inner cladding having an effective outer radius and a second effective refractive index, and (c) an outer cladding region concentrically surrounding the inner cladding having an effective thickness and a third effective refractive index, CHARACTERIZED IN THAT (d) the difference between the first and the third index is between about 0.1% and about 0.4% of the value of the third index, with the first index being larger than the third index, (e) the difference between the third and the second index is between about 1 times and about 3 times the difference between the first and the third index, with the third index being larger than the second index, (f) the effective core radius is between about 0.5 times and about 0.8 times the effective outer radius of the inner cladding, and (g) the effective outer radius of the inner cladding is at least about 5 μm.
Claim 17
Dependent Claim
25 words
Fiberguide of claim 14 wherein the refractive index of the core region is substantially constant over more than about 90% of the core cross section.
Claim 18
Dependent Claim
86 words
Fiberguide according to claims 14 or 15, wherein (h) the difference between the first and the third index is between about 0.15% and about 0.3% of the value of the third index, (i) the difference between the third and the second index is between about 1.5 times and about 2.5 times the difference between the first and the third index, (j) the core consists essentially of SiO 2 , and (i) the thickness of the outer cladding is at least about 8 times the core radius.
Claim 19
Dependent Claim
17 words
Fiberguide according to claim 16, wherein the inner cladding and the outer cladding comprise fluorine doped silica.
Claim 20
Dependent Claim
12 words
Fiberguide according to claim 16, wherein the core comprises germanium doped silica.
References Cited (Backward Citations)
US3997241A
Cited
US4217027A
Cited
US4217027B1
Cited
US4135901A
Cited
US4206967A
Cited
US3966446A
Cited
US4392715A
Cited
US4372647A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-03-06 | 1987-09-05 | 1988-03-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-03-06 | 1991-09-05 | 1992-03-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-03-06 | 1995-09-05 | 1996-03-06 | $7700.00 | Window Closed / Lapsed |