Patent US5099350A successfully refreshed from Google Patents.
US5099350A
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Method and device for the optical filtering and photodetection of intensity-modulated optical signals
Assignee: France Telecom R&D SA
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Filing: 1989-08-01
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Granted: 1992-03-24
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Expires: 2009-08-01
Abstract
Abstract Method and device for the optical filtering and photodetection of intensity-modulated optical signals. Signals are injected into at least one resonating type semiconductor laser amplifier (2) close to the active layer (14) of this amplifier, the latter being polarized below its threshold current and having at least one resonance wavelength adjusted so as to coincide with the wavelength of at least one of the optical signals in order for this optical signal to be amplified by the amplifier, and the voltage existing between the terminals of the amplifier is detected so as to obtain, in the form of an electric signal, the information carried by the amplified optical signal when the angle between the polarization direction of the latter and the direction of the active layer is small. Application for the embodiment of optical receivers.
Inventors
- 👤 Nakajima Hisao
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 18:12
CPC Classifications
H; H01; H01S; H01S5/00; H01S5/50; H01S5/5045; H01S5/0014; H01S5/10; H01S5/12; H01S5/0028; H01S5/5009; H01S5/5018
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
141 words
A method for the optical filtering and photodetection of optical signals which are linearly polarized and intensity-modulated in order to have them carry information, whereby optical signals are injected into at least one resonant type semiconductor laser amplifier close to the active layer of this amplifier, said amplifier being biased below its threshold current and having at least one resonance wavelength adjusted so as to coincide with the wavelength of at least one of the optical signals so that only this optical signal is amplified by the amplifier and whereby the electric voltage existing between the terminals of the amplifier is detected so as to obtain, in the form of an electric signal, the information carried by the amplified optical signal when the angle between the polarization direction of this optical signal and the direction of the active layer is small.
Claim 2
Independent Claim
141 words
A method for the optical filtering and photodetection of optical signals which are linearly polarized and intensity-modulated in order to have them carry information, whereby optical signals are injected into at least one resonant type semiconductor laser amplifier close to the active layer of this amplifier, said amplifier being biased below its threshold current and having at least one resonance wavelength adjusted so as to coincide with the wavelength of at least one of the optical signals so that only this optical signal is amplified by the amplifier and whereby the electric voltage existing between the terminals of the amplifier is detected so as to obtain, in the form of an electric signal, the information carried by the amplified optical signal when the angle between the polarization direction of this optical signal and the direction of the active layer is small.
Claim 3
Dependent Claim
29 words
A method according to claim 1, wherein the resonance wavelength is adjusted by adjusting the temperature of the amplifier and/or the intensity of the biasing current of this amplifier.
Claim 4
Dependent Claim
14 words
A method according to claim 1, wherein the amplifier is a Fabry-Perot type amplifier.
Claim 5
Dependent Claim
15 words
A method according to claim 1, wherein the amplifier is a distributed feedback type amplifier.
Claim 6
Independent Claim
157 words
A device for the optical filtering and photodetection of optical signals which are linearly polarized and intensity-modulated in order to have them carry information, said device comprising: at least one resonant type semiconductor laser amplifier having at least one resonance wavelength, the optical signals being intended to be injected into this amplifier close to the active layer of said amplifier, means to bias the amplifier below its threshold current, means to adjust the resonance wavelength of the amplifier so that it coincides with the wavelength of at least one of the optical signals so that only this optical signal is amplified by the amplifier, and means to detect the electric voltage existing between the terminals of the amplifier so as to obtain, in the form of an electric signal, the information carried by the amplified optical signal when the angle between the polarization direction of this optical signal and the direction of the active layer is small.
Claim 7
Independent Claim
157 words
A device for the optical filtering and photodetection of optical signals which are linearly polarized and intensity-modulated in order to have them carry information, said device comprising: at least one resonant type semiconductor laser amplifier having at least one resonance wavelength, the optical signals being intended to be injected into this amplifier close to the active layer of said amplifier, means to bias the amplifier below its threshold current, means to adjust the resonance wavelength of the amplifier so that it coincides with the wavelength of at least one of the optical signals so that only this optical signal is amplified by the amplifier, and means to detect the electric voltage existing between the terminals of the amplifier so as to obtain, in the form of an electric signal, the information carried by the amplified optical signal when the angle between the polarization direction of this optical signal and the direction of the active layer is small.
Claim 8
Dependent Claim
61 words
A device according to claim 5, wherein said resonant type semiconductor laser amplifier is single and intended to receive a plurality of intensity-modulated and linearly polarized optical signals whose respective wavelengths are different from each other and whose polarization directions are merged so as to have the resonance wavelength of the amplifier coincide with the wavelength of one of the signals.
Claim 9
Dependent Claim
27 words
A device according to claim 6, wherein the respective polarization directions of the optical signals are parallel to the direction of the active layer of the amplifier.
Claim 10
Dependent Claim
62 words
A device according to claim 5, comprising N resonant type semiconductor laser amplifiers, each intended to receive N linearly polarized and intensity-modulated optical signals whose respective wavelengths are different from each other, N being a whole number at least equal to 2 so as to have the resonance wavelengths of N amplifiers respectively coincide with the N wavelengths of the optical signals.
Claim 11
Dependent Claim
49 words
A device according to claim 8, wherein the respective active layers of the N amplifiers are parallel and the respective polarization directions of the N optical signals are parallel to each other, the directions of the respective active layers of the N amplifiers being parallel to these polarization directions.
Claim 12
Dependent Claim
87 words
A device according to claim 5, comprising two resonant type semiconductor laser amplifiers whose active layers are perpendicular and which are intended to each receive two linearly polarized and intensity-modulated optical signals of the same wavelength, the respective polarization directions of these signals being perpendicular with one of them being parallel to the active layer of one of the amplifiers so as to respectively detect the two optical signals by the two amplifiers when the resonance wavelength of each of said amplifiers coincide with said same wavelength.
Claim 13
Dependent Claim
13 words
A device according to claim 10, wherein the two optical signals are independent.
Claim 14
Dependent Claim
46 words
A device according to claim 10, wherein the two optical signals are digital and complementary to each other, the device further comprising subtracting means provided so as to output supply an electric signal equal to the difference between the electric signals respectively supplied by the amplifiers.
Claim 15
Dependent Claim
117 words
A device according to claim 5, comprising: two resonant type semiconductor laser amplifiers whose active layers are perpendicular and which are intended to each receive the same optical signal, this optical signal having a given wavelength and being linearly polarized and intensity-modulated, the polarization direction of this signal being parallel to the direction of the active layer of one of the amplifiers, and adding means provided to add up the electric signals respectively supplied by the two amplifiers when the resonance wavelength of each of the latter coincides with the given wavelength so as to obtain, in the form of an electric signal, the information carried by said optical signal at the output of the adding means.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-03-24 | 1995-09-23 | 1996-03-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-03-24 | 1999-09-23 | 2000-03-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-03-24 | 2003-09-23 | 2004-03-24 | $7700.00 | Window Closed / Lapsed |