US5074633A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Optical communication system comprising a fiber amplifier
Assignee: Furukawa Electric North America Inc
•
Filing: 1990-08-03
•
Granted: 1991-12-24
•
Expires: 2010-08-03
Abstract
Abstract Disclosed is an optical communication system comprising at least two optical fibers of dissimilar core sizes, joined by a fusion splice. In one embodiment, the larger-core fiber is a communication fiber, and the smaller-core fiber is an erbium-doped amplifier fiber. A taper region is included adjacent the splice. The diameter of the smaller-core fiber increases within the taper region as the splice is approached along the smaller-core fiber. The taper region is substantially free of constrictions. As a consequence of the taper region, the optical losses associated with the splice are relatively low, even when there is relatively high mismatch between the mode field diameters (at a signal wavelength) in the respective fibers.
Inventors
- 👤 Leonard G. Cohen
- 👤 John T. Krause
- 👤 William A. Reed
- 👤 Kenneth L. Walker
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 17:16
CPC Classifications
G; G02; G02B; G02B6/00; G02B6/24; G02B6/255; G02B6/2551; H; H01; H01S; H01S3/00; H01S3/05; H01S3/06; H01S3/063; H01S3/067; H01S3/06708; H01S3/06745
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
212 words
An optical communication system adapted for operation at least at one signal wavelength, comprising: a first optical fiber, the first fiber being an optical amplifier fiber, the first fiber including a first core that is doped with optically active ions capable of signal amplification by stimulated emission at the signal wavelength; and a second optical fiber joined to the first fiber, the second fiber having a second core that has a diameter greater than the diameter of the first core, the second fiber further having a mode field diameter at the signal wavelength of at least about 6 μm, characterized in that (a) the second and first fibers are joined by a fusion splice; (b) the first fiber has a mode field diameter at the signal wavelength of at most about 4 μm; (c) associated with the fusion splice is a taper region comprising a length of first fiber wherein the diameter of the first core increases as the splice is approached along the first fiber, the length of first fiber being at least about 0.5 mm and not more than about 5 mm; (d) the taper region is substantially free of constrictions; and (e) the fusion splice has a total splice loss at the signal wavelength of less than 0.3 dB.
Claim 2
Dependent Claim
212 words
An optical communication system adapted for operation at least at one signal wavelength, comprising: a first optical fiber, the first fiber being an optical amplifier fiber, the first fiber including a first core that is doped with optically active ions capable of signal amplification by stimulated emission at the signal wavelength; and a second optical fiber joined to the first fiber, the second fiber having a second core that has a diameter greater than the diameter of the first core, the second fiber further having a mode field diameter at the signal wavelength of at least about 6 μm, characterized in that (a) the second and first fibers are joined by a fusion splice; (b) the first fiber has a mode field diameter at the signal wavelength of at most about 4 μm; (c) associated with the fusion splice is a taper region comprising a length of first fiber wherein the diameter of the first core increases as the splice is approached along the first fiber, the length of first fiber being at least about 0.5 mm and not more than about 5 mm; (d) the taper region is substantially free of constrictions; and (e) the fusion splice has a total splice loss at the signal wavelength of less than 0.3 dB.
Claim 3
Dependent Claim
21 words
The optical communication system of claim 1, wherein the optically active ions are ions of at least one rare earth element.
Claim 4
Dependent Claim
15 words
The optical communication system of claim 1, wherein the optically active ions are erbium ions.
Claim 5
Dependent Claim
21 words
The optical communication system of claim 1, wherein the first core has an elemental composition that includes silicon, germanium, and aluminum.
References Cited (Backward Citations)
US3779628A
Cited
US3808549A
Cited
US4143940A
Cited
US4083625A
Cited
US4689065A
Cited
US4900114A
Cited
US4782491A
Cited
US4763976A
Cited
US4923279A
Cited
US5011251A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-12-23 | 1995-06-24 | 1995-12-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-12-23 | 1999-06-24 | 1999-12-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-12-23 | 2003-06-24 | 2003-12-24 | $7700.00 | Window Closed / Lapsed |