Patent US5325225A successfully refreshed from Google Patents.
US5325225A
Expired / Lapsed
US
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Method of optical transmission and optical transmitter used in the same
Assignee: NEC Corp
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Filing: 1993-01-06
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Granted: 1994-06-28
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Expires: 2013-01-06
Abstract
Abstract A method of optical transmission comprises steps of generating a light signal, controlling a wavelength of the light signal in accordance with a correcting signal, and modulating an intensity of the light signal supplied from the light source to generate an output light signal in accordance with a modulating signal. The wavelength change of the light signal generated by the light source coincides with the wavelength change which occurs during the modulating step, so that the wavelength change is cancelled in the output light signal. An optical transmitter used in the method comprises a light source which generates a light signal, a correcting signal generating circuit which supplies the light source with a correcting signal for changing the wavelength of the light signal generated by the light source, and an optical modulator which modulates an intensity of the light signal supplied from the light source to generate an output light signal in accordance with a modulating signal.
Inventors
- 👤 Tetsuyuki Suzaki
- 👤 Naoya Henmi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 20:54
CPC Classifications
H; H04; H04B; H04B10/00; H04B10/50; H04B10/501; H04B10/503; H04B10/504; H04B10/505
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
105 words
A method of optical transmission, comprising the steps of: emitting a light from a light source; modulating an intensity of said light supplied form said light source to generate an output light signal in accordance with a modulating signal; controlling a wavelength of said light by adding a correction signal to an electric bias of said light source such that said wavelength of said light supplied from said light source is adjusted to compensate for and cancel a wavelength change which occurs in said output light signal during said modulating step; and generating said correcting signal in response to level changes in said modulating signal.
Claim 2
Independent Claim
105 words
A method of optical transmission, comprising the steps of: emitting a light from a light source; modulating an intensity of said light supplied form said light source to generate an output light signal in accordance with a modulating signal; controlling a wavelength of said light by adding a correction signal to an electric bias of said light source such that said wavelength of said light supplied from said light source is adjusted to compensate for and cancel a wavelength change which occurs in said output light signal during said modulating step; and generating said correcting signal in response to level changes in said modulating signal.
Claim 3
Dependent Claim
24 words
A method of optical transmission, according to claim 1, wherein: said emitting step is a step of emitting said light from a semiconductor laser.
Claim 4
Dependent Claim
44 words
A method of optical transmission, according to claim 1, wherein: said modulating step is a step of modulating said intensity of said light signal dependent on an optical absorption coefficient which is changed by applying an electric field in accordance with said modulating signal.
Claim 5
Dependent Claim
45 words
A method of optical transmission, according to claim 1, wherein: said modulating step is a step of modulating said intensity of said light dependent on an optical length of optical waveguides which is changed by applying an electric field in accordance with said modulating signal.
Claim 6
Dependent Claim
21 words
A method of optical transmission, according to claim 1, wherein: said correcting signal is a differentiated signal of said modulating signal.
Claim 7
Dependent Claim
21 words
A method of optical transmission, according to claim 1, wherein: said correcting signal is a differentiated signal of a clock signal.
Claim 8
Dependent Claim
30 words
A method of optical transmission, according to claim 1, wherein: said correcting signal is a differentiated signal of a clock signal, and said modulating signal is a RZ code signal.
Claim 9
Dependent Claim
61 words
A method of optical transmission, according to claim 5, further comprising a step of: generating a delayed signal of said modulating signal; wherein said modulating of said intensity of said light signal is carried out in accordance with said delayed signal, so that a wavelength change of said light signal coincides with said wavelength change which occurs during said modulating step.
Claim 10
Dependent Claim
120 words
An optical transmitter, comprising: a light source which generates a light having a predetermined wavelength; an optical modulator which modulates an intensity of said light supplied form said light source to generate an output light signal in accordance with a modulating signal; means, coupled to said light source, for controlling a wavelength of said light generated by said light source in accordance with a correcting signal such that said wavelength of said light supplied from said light source is adjusted to compensate for and cancel a wavelength change which occurs in said output light signal during modulation by said optical modulator; and a correcting signal generation means which generates said correcting signal by detecting level changes of said modulation signal.
Claim 11
Dependent Claim
120 words
An optical transmitter, comprising: a light source which generates a light having a predetermined wavelength; an optical modulator which modulates an intensity of said light supplied form said light source to generate an output light signal in accordance with a modulating signal; means, coupled to said light source, for controlling a wavelength of said light generated by said light source in accordance with a correcting signal such that said wavelength of said light supplied from said light source is adjusted to compensate for and cancel a wavelength change which occurs in said output light signal during modulation by said optical modulator; and a correcting signal generation means which generates said correcting signal by detecting level changes of said modulation signal.
Claim 12
Dependent Claim
20 words
An optical transmitter, according to claim 9, wherein: said light source is a semiconductor laser which generates a laser light.
Claim 13
Dependent Claim
30 words
An optical transmitter, according to claim 9, wherein: said optical modulator is an optical modulator selected from one of an electroabsorption type optical modulator and a Mach-Zender type optical modulator.
Claim 14
Dependent Claim
28 words
An optical transmitter, according to claim 9, wherein: said producing means includes means for generating a differentiated signal of said modulating signal for supplying to said light source.
Claim 15
Dependent Claim
62 words
An optical transmitter, according to claim 9, further comprising: means for generating a delayed signal of said modulating signal for supplying to said optical modulator; wherein said optical modulator modulates said intensity of said light signal in accordance with said delayed modulating signal, so that said wavelength change of said light signal coincides with the wavelength change which occurs during intensity modulation.
Claim 16
Dependent Claim
28 words
An optical transmitter, according to claim 9, wherein: said producing means includes means for generating a differentiated signal of a clock signal for supplying to said light source.
Claim 17
Dependent Claim
22 words
An optical transmitter according to claim 9, wherein said correcting signal produced by said producing means inversely corresponds to said wavelength change.
Claim 18
Dependent Claim
22 words
An optical transmitter according to claim 13, wherein said correcting signal produced by said producing means inversely corresponds to said wavelength change.
Claim 19
Dependent Claim
24 words
A method of optical transmission according to claim 1, wherein said correcting signal produced by said producing step inversely corresponds to said wavelength change.
References Cited (Backward Citations)
US4525687A
Cited
US4669086A
Cited
US4660206A
Cited
US4744616A
Cited
US4912526A
Cited
US4805235A
Cited
US4837526A
Cited
US4835780A
Cited
US4958359A
Cited
US4888777A
Cited
US4913506A
Cited
US5073331A
Cited
US4912716A
Cited
US5128950A
Cited
US5170274A
Cited
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| 3.5 Years (Year 4) | 1997-06-27 | 1997-12-27 | 1998-06-28 | $2000.00 | Window Closed / Lapsed |
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