EP0459685A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Multi-stage optical amplifier
Assignee: AT&T Inc
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Filing: 1991-05-21
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Granted: —
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Expires: 2011-05-21
Abstract
Abstract This invention relates to an Erbium-doped fiber amplifier having multiple stages (12,14) of amplification for providing enhanced performance. More specifically, optical means (20,28) is located intermediate first and second stages of doped optical amplifying fibers adapted to receive a pump signal at a pump wavelength where the optical means is adapted to modify the net gain characteristics of the multi-stage amplifier. Presently, all known Erbium-doped fiber amplifiers utilize relatively simple single stage amplifiers which support required ancillary optically passive components such as isolators, filters, pump multiplexers, power monitors and the like at either end of the amplifier. This requirement of having the passive optical element at an end of the optical amplifier not only lends to relatively stringent design and fabrication tolerances for a high performance optical amplifier, but it restricts the design of the Erbium-doped fiber amplifier to an embodiment which prevents exploitation of the various unique properties of the Erbium-doped fiber amplifier.
Inventors
- 👤 David J. Digiovanni
- 👤 Clinton Randy Giles
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-08 16:13
CPC Classifications
H; H01; H01S; H01S3/00; H01S3/05; H01S3/06; H01S3/063; H01S3/067; H01S3/06754; H01S3/06758; H01S3/06787; H01S3/09; H01S3/091; H01S3/094; H01S3/094003; H01S3/094011; H01S3/09408
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
104 words
An optical amplifier comprising a first stage of amplification (12) comprising a doped optical amplifying fiber (18) having an input port and an output port (36), a second stage of amplificiation (14) comprising a doped optical amplifying fiber (19) having an input port (38) and an output port, means (26,34) for generating a pump signal at a pump wavelength coupled optically to said first and second doped optical amplifying fibers, and optical means (16) connecting said output port of said first stage to said input port of said second stage, said optical means being selected from the group consisting of isolator, filter and multiplexer.
Claim 2
Dependent Claim
20 words
An amplifier as claimed in claim 1 wherein each of said first and second stages comprises an Erbium-doped optical fiber.
Claim 3
Dependent Claim
45 words
An amplifier as claimed in claim 2 wherein said means for generating a pump signal comprises a first laser diode for pumping said Erbium-doped optical fiber of said first stage and a second laser diode for pumping said Erbium-doped optical fiber of said second stage.
Claim 4
Dependent Claim
19 words
An amplifier as claimed in claim 1 wherein said means for generating a pump signal comprises a laser diode.
Claim 5
Dependent Claim
15 words
An amplifier as claimed in any preceding claim wherein said isolator comprises an optical diode.
Claim 6
Dependent Claim
15 words
An amplifier as claimed in any preceding claim wherein said filter comprises a diffraction grating.
Claim 7
Dependent Claim
19 words
An amplifier as claimed in any one of claims 1 to 5 wherein said filter comprises a thin film.
Claim 8
Dependent Claim
19 words
An amplifiier as claimed in any one of claims 1 to 5 wherein said filter comprises an absorbing filter.
Claim 9
Dependent Claim
35 words
An amplifier as claimed in any preceding claim wherein said filter comprises means for reducing energy in the form of spontaneous emission from the first stage from reaching and causing saturation of the second stage.
Claim 10
Dependent Claim
15 words
An amplifier as claimed in any preceding claim wherein said multiplexer comprises a defraction grating.
Claim 11
Dependent Claim
19 words
An amplifier as claimed in any one of claims 1 to 9 wherein said multiplexer comprises a thin film.
Claim 12
Dependent Claim
50 words
An amplifier as claimed in any preceding claim wherein said means for generating a pump signal at a pump wavelength is coupled to the output port of said doped optical fiber of said first stage and to the input port of said doped and optical fiber of said second stage.
Claim 13
Dependent Claim
213 words
A multi-stage optical amplifier comprising a first stage of amplification (12) comprising an Erbium-doped optical amplifying fiber having a first port (40) and a second port, a second stage of amplification (14) comprising an Erbium-doped optical amplifying fiber having a first port and a second port (30), a first coupler (20) coupled to the second port of said first stage of amplification, a second coupler (28) coupled to the first port of said second stage of amplification, means (26,34) for generating a pump signal at a pump wavelength coupled to said first stage of amplification through said first coupler and to said second stage of amplification through said second coupler, a third coupler (21) interposed between said first coupler and said second coupler, a fourth coupler (25) interposed between said third coupler and said second coupler, a first optical isolator (15) and a first optical filter (17) interposed between said third and fourth couplers to pass a signal of a first wavelength from said first stage of amplification to said second stage of amplification, and a second optical isolator (52) and a second optical filter (54) interposed between said third and fourth couplers to pass a signal of a second wavelength from said second stage of amplification to said first stage of amplification.
Claim 14
Dependent Claim
46 words
An amplifier as claimed in claim 13 wherein said third and fourth couplers comprises 3dB couplers, said first and second optical isolators comprise optical diodes, said first and second optical filters comprise interference filters, and said means for generating a pump signal comprises a laser diode.
References Cited (Backward Citations)
No citation records indexed.
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