Method and Device for Reducing Laser Phase Noise
First Claim
1. A device for reducing a phase noise of a laser signal from a laser source, the device comprising:
- a first current generator for supplying a main driving current to the laser source for producing the laser signal;
a phase noise detector responsive to the laser signal for generating a phase error signal; and
a second current generator responsive to the phase error signal for generating a compensation current added to the main driving current supplied to the laser source for generating a phase-adjusted laser signal;
wherein the phase noise detector and the second current generator form a phase stabilization loop for reducing the phase noise of the laser signal.
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Abstract
The present invention relates to a method and device for reducing the phase noise of a laser signal from a laser source. This device comprises a first current generator for supplying a driving current to the laser source in view of producing the laser signal. A phase noise detector is responsive to the laser wavelength for generating a phase error signal and a second current generator is responsive to the phase error signal for generating a compensation current added to the driving current supplied to the laser source for generating a phase-adjusted laser signal. The device therefore defines a phase stabilization loop formed by the phase noise detector and the second current generator, for reducing the phase noise of the laser signal.
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Citations
21 Claims
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1. A device for reducing a phase noise of a laser signal from a laser source, the device comprising:
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a first current generator for supplying a main driving current to the laser source for producing the laser signal; a phase noise detector responsive to the laser signal for generating a phase error signal; and a second current generator responsive to the phase error signal for generating a compensation current added to the main driving current supplied to the laser source for generating a phase-adjusted laser signal; wherein the phase noise detector and the second current generator form a phase stabilization loop for reducing the phase noise of the laser signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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16. A method for reducing a phase noise of a laser signal from a laser source, the method comprising:
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generating through a first current generator a main driving current to be supplied to the laser source for producing the laser signal; detecting a phase noise in the laser signal; generating a phase error signal in response to the detected phase noise; and generating, in response to the phase error signal and through a second current generator, a compensation current to be added to the main driving current supplied to the laser source in view of producing a phase adjusted laser signal; wherein the operations of detecting the phase noise in the laser signal, generating the phase error signal in response to the detected phase noise and generating the compensation current in response to the error signal define a phase stabilization loop for reducing the phase noise of the laser signal. - View Dependent Claims (17, 18)
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19. A detector for detecting wavelength drifting of a laser signal, comprising:
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a wavelength discrimination filter supplied with the laser signal;
the wavelength discrimination filter being so configured as to reflect a portion of the laser signal and to transmit a portion of the laser signal;a first photodetector connected to the wavelength discrimination filter for measuring the transmitted portion of the laser signal; and a second photodetector connected to the wavelength discrimination filter for measuring the reflected portion of the laser signal; wherein the wavelength discrimination filter is a periodic high slope wavelength discrimination filter, the periodic high slope wavelength discrimination filter is a Fabry-Perot filter and the Fabry-Perot filter is made of two Bragg gratings spaced apart by a gap and formed inside an optical fiber; and wherein measurements of the transmitted and the reflected laser signal portions are usable for detecting the wavelength drifting of the laser signal. - View Dependent Claims (20, 21)
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Specification