Patent US5177634A successfully refreshed from Google Patents.
US5177634A
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US
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High gain limiting erbium-doped fiber amplifier with wide dynamic range
Assignee: Nytell Software LLC
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Filing: 1991-10-25
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Granted: 1993-01-05
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Expires: 2011-10-25
Abstract
Abstract An optical limiting amplifier is disclosed having a high gain over a wide dynamic range of input power levels. The amplifier has an input stage (102) and an output stage (103), each of which includes an erbium-doped fiber amplifier (104, 106). The erbium-doped fiber amplifier in the input stage provides a high gain in order to saturate the amplifier in the second stage. The erbium-doped fiber amplifier in the output stage is fabricated with a small core diameter to saturate at reasonably small signal levels, and has a relatively lower total number of erbium ions in order to limit amplification once deep saturation is reached.
Inventors
- 👤 Winston I. Way
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 21:39
CPC Classifications
H; H01; H01S; H01S3/00; H01S3/05; H01S3/06; H01S3/063; H01S3/067; H01S3/06754; H01S3/06758; H01S3/06779
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
77 words
An optical limiting amplifier comprising: an input stage comprising a first erbium-doped fiber amplifier; and an output stage in cascade with said input stage comprising a second erbium-doped fiber amplifier, the fiber in said second erbium-doped fiber having a fiber core diameter of less than about 4 μm and a product of erbium ion concentration (in ppm) times erbium core area (in m 2 ) times fiber length (in m) of less than about 8.5×10 -9 .
Claim 2
Dependent Claim
77 words
An optical limiting amplifier comprising: an input stage comprising a first erbium-doped fiber amplifier; and an output stage in cascade with said input stage comprising a second erbium-doped fiber amplifier, the fiber in said second erbium-doped fiber having a fiber core diameter of less than about 4 μm and a product of erbium ion concentration (in ppm) times erbium core area (in m 2 ) times fiber length (in m) of less than about 8.5×10 -9 .
Claim 3
Dependent Claim
27 words
An optical limiting amplifier in accordance with claim 1 wherein the concentration of erbium ions in the second erbium-doped fiber amplifier is less than about 100 ppm.
Claim 4
Dependent Claim
24 words
An optical limiting amplifier in accordance with claim 1 wherein the second erbium-doped fiber amplifier has a length of less than about 12 m.
Claim 5
Dependent Claim
54 words
An optical limiting amplifier in accordance with claim 1 wherein said input stage further comprises first optical bandpass filter means for filtering the spontaneous emission noise of the first erbium-doped fiber amplifier, and said output stage further comprises second optical bandpass filter for filtering the spontaneous emission noise of the second erbium-doped fiber amplifier.
Claim 6
Dependent Claim
48 words
An optical limiting amplifier in accordance with claim 4 wherein said input stage further comprises first optical isolating means for isolating said first erbium-doped fiber amplifier from optical reflections, and said output stage comprises second optical isolating means for isolating said second erbium-doped fiber amplifier from optical reflections.
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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) | 1996-01-05 | 1996-07-06 | 1997-01-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-01-05 | 2000-07-06 | 2001-01-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-01-05 | 2004-07-06 | 2005-01-05 | $7700.00 | Window Closed / Lapsed |