US6055092A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Multi-wavelength light amplifier
Assignee: Fujitsu Ltd
•
Filing: 1996-05-28
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Granted: 2000-04-25
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Expires: 2016-05-28
Abstract
Abstract A multi-wavelength light amplifier includes a first-stage light amplifier which has a first light amplifying optical fiber amplifying a light input, a second-stage light amplifier which has a second light amplifying optical fiber amplifying a first light output from the first-stage light amplifier, and an optical system which maintains a second light output of the second-stage light amplifier at a constant power level. The first-stage and second-stage light amplifiers have different gain vs wavelength characteristics so that the multi-wavelength light amplifier has no wavelength-dependence of a gain thereof.
Inventors
- 👤 Yasushi Sugaya
- 👤 Miki Takeda
- 👤 Susumu Kinoshita
- 👤 Terumi Chikama
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 01:26
CPC Classifications
H; H04; H04B; H04B10/00; H04B10/29; H04B10/291; H04B10/293; H04B10/294; H04B10/296; H01; H01S; H01S3/00; H01S3/05; H01S3/06; H01S3/063; H01S3/067; H01S3/06754; H01S3/06758; H01S3/10; H01S3/13; H01S3/1301; H01S3/13013; H04J; H04J14/00; H04J14/02; H04J14/0221; H04J14/02216; H01S2301/00; H01S2301/04; H01S3/10007; H01S3/10015
Claims Analysis
Total Claims: 40
Claim 1
Independent Claim
91 words
An apparatus comprising: a multi-stage optical amplifying unit, for amplifying an input light, which includes a first-stage optical amplifier which has an optical fiber for amplifying the input light to produce a first-stage amplified light; a second-stage optical amplifier which has an optical fiber for amplifying the first-stage amplified light, to produce a second-stage amplified light; and an attenuator positioned between the first-stage optical amplifier and the second-stage optical amplifier, to attenuate the power level of the first-stage amplified light and thereby control a power level of the second-stage amplified light.
Claim 2
Independent Claim
91 words
An apparatus comprising: a multi-stage optical amplifying unit, for amplifying an input light, which includes a first-stage optical amplifier which has an optical fiber for amplifying the input light to produce a first-stage amplified light; a second-stage optical amplifier which has an optical fiber for amplifying the first-stage amplified light, to produce a second-stage amplified light; and an attenuator positioned between the first-stage optical amplifier and the second-stage optical amplifier, to attenuate the power level of the first-stage amplified light and thereby control a power level of the second-stage amplified light.
Claim 3
Dependent Claim
30 words
An apparatus as in claim 1, wherein the attenuator attenuates the power level of the first-stage amplified light on the basis of the power level of the second-stage amplified light.
Claim 4
Independent Claim
79 words
An apparatus comprising: a multi-stage optical amplifying unit, for amplifying an input light, which includes a first-stage optical amplifier which has an optical fiber for amplifying the input light, to produce a first-stage amplified light; a second-stage optical amplifier which has an optical fiber for amplifying the first-stage amplified light, to produce a second-stage amplified light; and a level controller controlling the power level of the first-stage amplified light based on a power level of the second-stage amplified light.
Claim 5
Independent Claim
79 words
An apparatus comprising: a multi-stage optical amplifying unit, for amplifying an input light, which includes a first-stage optical amplifier which has an optical fiber for amplifying the input light, to produce a first-stage amplified light; a second-stage optical amplifier which has an optical fiber for amplifying the first-stage amplified light, to produce a second-stage amplified light; and a level controller controlling the power level of the first-stage amplified light based on a power level of the second-stage amplified light.
Claim 6
Dependent Claim
24 words
An apparatus as in claim 3, wherein the level controller comprises an attenuator positioned between the first-stage optical amplifier and the second-stage optical amplifier.
Claim 7
Dependent Claim
28 words
An apparatus as in claim 4, wherein the attenuator attenuates the power level of the first-stage amplified light, to control a power level of the second-stage amplified light.
Claim 8
Dependent Claim
30 words
An apparatus as in claim 5, wherein the attenuator attenuates the power level of the first-stage amplified light on the basis of the power level of the second-stage amplified light.
Claim 9
Dependent Claim
33 words
An apparatus as in claim 3, wherein the first-stage and second-stage optical amplifiers have different gain versus wavelength characteristics so that the multi-stage optical amplifying unit has a gain with substantially no wavelength-dependence.
Claim 10
Dependent Claim
33 words
An apparatus as in claim 4, wherein the first-stage and second-stage optical amplifiers have different gain versus wavelength characteristics so that the multi-stage optical amplifying unit has a gain with substantially no wavelength-dependence.
Claim 11
Independent Claim
94 words
An apparatus comprising: a multi-stage optical amplifying unit, for amplifying an input light, which includes a first-stage optical amplifier which has an optical fiber for amplifying the input light, to produce a first-stage amplified light; a second-stage optical amplifier which has an optical fiber for amplifying the first-stage amplified light, to produce a second-stage amplified light; and a level controller including an attenuator positioned between the first-stage optical amplifier and the second-stage optical amplifier, to control a power level of the first-stage amplified light depending on a power level of the second-stage amplified light.
Claim 12
Independent Claim
94 words
An apparatus comprising: a multi-stage optical amplifying unit, for amplifying an input light, which includes a first-stage optical amplifier which has an optical fiber for amplifying the input light, to produce a first-stage amplified light; a second-stage optical amplifier which has an optical fiber for amplifying the first-stage amplified light, to produce a second-stage amplified light; and a level controller including an attenuator positioned between the first-stage optical amplifier and the second-stage optical amplifier, to control a power level of the first-stage amplified light depending on a power level of the second-stage amplified light.
Claim 13
Dependent Claim
30 words
An apparatus as in claim 9, wherein the attenuator attenuates the power level of the first-stage amplified light on the basis of the power level of the second-stage amplified light.
Claim 14
Dependent Claim
33 words
An apparatus as in claim 9, wherein the first-stage and second-stage optical amplifiers have different gain versus wavelength characteristics so that the multi-stage optical amplifying unit has a gain with substantially no wavelength-dependence.
Claim 15
Independent Claim
67 words
A method comprising the steps of: (a) optically amplifying an input light to produce a first-stage amplified light; (b) optically amplifying the first-stage amplified light to produce a second-stage amplified light; (c) controlling the power level of the first-stage amplified light in accordance with a power level of the second-stage amplified light; and (d) performing said steps (a), (b) and (c) by a multi-stage optical amplifying unit.
Claim 16
Independent Claim
67 words
A method comprising the steps of: (a) optically amplifying an input light to produce a first-stage amplified light; (b) optically amplifying the first-stage amplified light to produce a second-stage amplified light; (c) controlling the power level of the first-stage amplified light in accordance with a power level of the second-stage amplified light; and (d) performing said steps (a), (b) and (c) by a multi-stage optical amplifying unit.
Claim 17
Independent Claim
86 words
An apparatus comprising: a multi-stage optical amplifying unit, for amplifying an input light, which includes: a first-stage optical amplifier which has an optical fiber for amplifying the input light, to produce a first-stage amplified light; a second-stage optical amplifier which has an optical fiber for amplifying the first-stage amplified light, to produce a second-stage amplified light; and a level controller detecting a power level of the second-stage amplified light, and controlling the power level of the first-stage amplified light in accordance with said detected power level.
Claim 18
Independent Claim
86 words
An apparatus comprising: a multi-stage optical amplifying unit, for amplifying an input light, which includes: a first-stage optical amplifier which has an optical fiber for amplifying the input light, to produce a first-stage amplified light; a second-stage optical amplifier which has an optical fiber for amplifying the first-stage amplified light, to produce a second-stage amplified light; and a level controller detecting a power level of the second-stage amplified light, and controlling the power level of the first-stage amplified light in accordance with said detected power level.
Claim 19
Dependent Claim
33 words
An apparatus as in claim 3, wherein the level controller controls the power level of the first-stage amplified light to maintain the power level of the second-stage amplified light at a constant level.
Claim 20
Dependent Claim
33 words
An apparatus as in claim 9, wherein the level controller controls the power level of the first-stage amplified light to maintain the power level of the second-stage amplified light at a constant level.
Claim 21
Dependent Claim
32 words
A method as in claim 12, wherein said controlling controls the power level of the first-stage amplified light to maintain a power level of the second-stage amplified light at a constant level.
Claim 22
Independent Claim
97 words
An apparatus comprising: a multi-stage optical amplifying unit, for amplifying an input light, which includes: a first-stage optical amplifier which has an optical fiber for amplifying the input light, to produce a first-stage amplified light; a second-stage optical amplifier which has an optical fiber for amplifying the first-stage amplified light, to produce a second-stage amplified light at an output port of the second-stage optical amplifier; and a level controller controlling a power level of the first-stage amplified light based on a power level of the second-stage amplified light at the output port of the second-stage optical amplifier.
Claim 23
Independent Claim
97 words
An apparatus comprising: a multi-stage optical amplifying unit, for amplifying an input light, which includes: a first-stage optical amplifier which has an optical fiber for amplifying the input light, to produce a first-stage amplified light; a second-stage optical amplifier which has an optical fiber for amplifying the first-stage amplified light, to produce a second-stage amplified light at an output port of the second-stage optical amplifier; and a level controller controlling a power level of the first-stage amplified light based on a power level of the second-stage amplified light at the output port of the second-stage optical amplifier.
Claim 24
Dependent Claim
34 words
An apparatus as in claim 17, wherein the level controller comprises an attenuator positioned between the first-stage optical amplifier and the second-stage optical amplifier, to control the power level of the first-stage amplified light.
Claim 25
Dependent Claim
43 words
An apparatus as in claim 3, wherein the level controller comprises a detector detecting the power level of the second-stage amplified light, the level controller controlling the power level of the first-stage amplified light based on the power level detected by the detector.
Claim 26
Dependent Claim
43 words
An apparatus as in claim 4, wherein the level controller comprises a detector detecting the power level of the second-stage amplified light, the level controller controlling the power level of the first-stage amplified light based on the power level detected by the detector.
Claim 27
Dependent Claim
17 words
An apparatus as in claim 4, wherein the attenuator is an optical attenuator having a variable attenuation.
Claim 28
Dependent Claim
43 words
An apparatus as in claim 9, wherein the level controller comprises a detector detecting the power level of the second-stage amplified light, the level controller controlling the power level of the first-stage amplified light based on the power level detected by the detector.
Claim 29
Dependent Claim
17 words
An apparatus as in claim 9, wherein the attenuator is an optical attenuator having a variable attenuation.
Claim 30
Dependent Claim
36 words
A method as in claim 12, further comprising: detecting the power level of the second-stage amplified light, wherein said controlling controls the power level of the first-stage amplified light in accordance with said detected power level.
Claim 31
Dependent Claim
22 words
An apparatus as in claim 13, wherein the level controller comprises a detector detecting the power level of the second-stage amplified light.
Claim 32
Dependent Claim
52 words
An apparatus as in claim 17, wherein the level controller comprises a detector detecting the power level of the second-stage amplified light at the output port of the second-stage optical amplifier, the level controller controlling the power level of the first-stage amplified light based on the power level detected by the detector.
Claim 33
Independent Claim
98 words
An apparatus comprising: a multi-stage optical amplifying unit, for amplifying an input light, which includes a first-stage optical amplifier amplifying the input light, to produce a first-stage amplified light; a second-stage optical amplifier amplifying the first-stage amplified light, to produce a second-stage amplified light; a detector detecting a power level of the second-stage amplified light; and an optical attenuator having a variable attenuation and positioned between the first-stage optical amplifier and the second-stage optical amplifier to attenuate the first-stage amplified light, the attenuation of the optical attenuator being controlled based on the power level detected by the detector.
Claim 34
Independent Claim
98 words
An apparatus comprising: a multi-stage optical amplifying unit, for amplifying an input light, which includes a first-stage optical amplifier amplifying the input light, to produce a first-stage amplified light; a second-stage optical amplifier amplifying the first-stage amplified light, to produce a second-stage amplified light; a detector detecting a power level of the second-stage amplified light; and an optical attenuator having a variable attenuation and positioned between the first-stage optical amplifier and the second-stage optical amplifier to attenuate the first-stage amplified light, the attenuation of the optical attenuator being controlled based on the power level detected by the detector.
Claim 35
Independent Claim
67 words
A method comprising the steps of: (a) optically amplifying an input light to produce a first-stage amplified light; (b) optical amplifying the first-stage amplified light to produce a second-stage amplified light; (c) attenuating a power level of the first-stage amplified light in accordance with a power level of the second-stage amplified light; and (d) performing said steps (a), (b) and (c) by a multi-stage optical amplifying unit.
Claim 36
Independent Claim
67 words
A method comprising the steps of: (a) optically amplifying an input light to produce a first-stage amplified light; (b) optical amplifying the first-stage amplified light to produce a second-stage amplified light; (c) attenuating a power level of the first-stage amplified light in accordance with a power level of the second-stage amplified light; and (d) performing said steps (a), (b) and (c) by a multi-stage optical amplifying unit.
Claim 37
Independent Claim
107 words
A method comprising the steps of: (a) providing a multi-stage optical amplifying unit; (b) optically amplifying an input light by a stage of the multi-stage optical amplifying unit to produce a first-stage amplified light; (c) optical amplifying the first-stage amplified light by a stage of the multi-stage optical amplifying unit, different from said stage in step (b), to produce a second-stage amplified light; (d) attenuating the power level of the first-stage amplified light in accordance with a power level of the second-stage amplified light, by the multi-stage optical amplifying unit; and (e) outputting the second-stage amplified light as an output light of the multi-stage optical amplifying unit.
Claim 38
Independent Claim
107 words
A method comprising the steps of: (a) providing a multi-stage optical amplifying unit; (b) optically amplifying an input light by a stage of the multi-stage optical amplifying unit to produce a first-stage amplified light; (c) optical amplifying the first-stage amplified light by a stage of the multi-stage optical amplifying unit, different from said stage in step (b), to produce a second-stage amplified light; (d) attenuating the power level of the first-stage amplified light in accordance with a power level of the second-stage amplified light, by the multi-stage optical amplifying unit; and (e) outputting the second-stage amplified light as an output light of the multi-stage optical amplifying unit.
Claim 39
Independent Claim
138 words
A method comprising the steps of: (a) transmitting an optical signal through an optical fiber; (b) providing a multi-stage optical amplifying unit; (c) optically amplifying the optical signal received through the optical fiber by a stage of the multi-stage optical amplifying unit, to produce a first-stage amplified optical signal; (d) optically amplifying the first-stage amplified optical signal by a stage of the multi-stage optical amplifying unit different from said stage in step (c), to produce a second-stage amplified optical signal; (e) controlling the power level of the first-stage amplified optical signal in accordance with a power level of the second-stage amplified optical signal by the multi-stage optical amplifying unit; (f) outputting the second-stage amplified optical signal as an output optical signal of the multi-stage optical amplifying unit; and (g) transmitting the output optical signal through an optical fiber.
Claim 40
Independent Claim
138 words
A method comprising the steps of: (a) transmitting an optical signal through an optical fiber; (b) providing a multi-stage optical amplifying unit; (c) optically amplifying the optical signal received through the optical fiber by a stage of the multi-stage optical amplifying unit, to produce a first-stage amplified optical signal; (d) optically amplifying the first-stage amplified optical signal by a stage of the multi-stage optical amplifying unit different from said stage in step (c), to produce a second-stage amplified optical signal; (e) controlling the power level of the first-stage amplified optical signal in accordance with a power level of the second-stage amplified optical signal by the multi-stage optical amplifying unit; (f) outputting the second-stage amplified optical signal as an output optical signal of the multi-stage optical amplifying unit; and (g) transmitting the output optical signal through an optical fiber.
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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) | 2003-04-25 | 2003-10-25 | 2004-04-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2007-04-25 | 2007-10-25 | 2008-04-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2011-04-25 | 2011-10-25 | 2012-04-25 | $7700.00 | Window Closed / Lapsed |