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US 6,785,308 B2Granted
Spectral conditioning system and method
AssigneeNortel Networks Limited
InventorsPeter J. Dyer, Tom M. Luk, Jean-Philippe Martel
Life of this patent
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Abstract
A system and method for spectral conditioning an optical signal. An optical filter has an input for receiving an emitted optical signal and an output providing a filtered optical signal. The filter has a corresponding filter profile which includes a high wavelength skirt at an upper wavelength region of the filter profile. A laser is optically coupled to the optical filter input and emits the emitted optical signal. The laser is controllable to emit the optical signal at a wavelength proximate to the optical filter high wavelength skirt.
Claims17
An optical spectral conditioning system, comprising:
- a laser emitting an optical signal, the laser having a back facet emitting a first portion of the optical signal and a front face emitting a second portion of the optical signal;
- a first monitor optically coupled to the back facet of the laser, the first monitor generating a first electrical signal corresponding to the first portion of the optical signal;
- an optical bandpass filter receiving the second portion of the optical signal from the front face of the laser and providing an optically filtered bandpass output, the optical bandpass filter having filtering characteristics defined by a filter profile, the filter profile including a high wavelength skirt at an upper wavelength region of the filter profile;
- a second monitor optically coupled to the output of optical bandpass filter, the second monitor generating a second electrical signal corresponding to the light emitted by the output of the bandpass filter;
- and
- a comparator receiving the first electrical signal and the second electrical signal, the comparator generating a dithering signal based on the first electrical signal and the second electrical signal, the dithering signal causing the laser to emit the first optical signal at the wavelength proximate to the optical filter high wavelength skirt.
3 more elements
A method for spectrally conditioning an optical signal emitted by a laser, the method comprising:
- using the laser to emit a first portion and a second portion of an optical signal;
- generating a first electrical signal corresponding to the first portion of the optical signal;
- producing an optically filtered bandpass output based on the second portion of the optical signal using a filter having filtering characteristics defined by a filter profile, the filter profile including a high wavelength skirt at an upper wavelength region of the filter profile;
- generating a second electrical signal corresponding to the optically filtered bandpass output;
- generating a dithering signal based on the first electrical signal and the second electrical signal;
- and
- operating the laser to emit the second portion of the optical signal at the wavelength proximate to the optical filter high wavelength skirt based on the dithering signal.
4 more elements
A method for spectrally conditioning an optical signal emitted by a directly modulated laser, the method comprising:
- using the directly modulated laser to emit a first portion and a second portion of an optical signal;
- generating a first electrical signal corresponding to the first portion of the optical signal;
- producing an optically filtered bandpass output based on the second portion of the optical signal using a filter having filtering characteristics defined by a filter profile, the filter profile including a high wavelength skirt at an upper wavelength region of the filter profile;
- generating a second electrical signal corresponding to the optically filtered bandpass output;
- generating a dithering signal based on the first electrical signal and the second electrical signal;
- and
- operating the directly modulated laser to emit the second portion of the optical signal at the wavelength proximate to the optical filter high wavelength skirt based on the dithering signal.
4 more elements
An optical spectral conditioning system, comprising:
- a directly modulated laser emitting an optical signal, the directly modulated laser having a back facet emitting a first portion of the optical signal and a front face emitting a second portion of the optical signal;
- a first monitor optically coupled to the back facet of the laser, the first monitor generating a first electrical signal corresponding to the first portion of the optical signal;
- an optical bandpass filter receiving the second portion of the optical signal from the front face of the laser and providing an optically filtered bandpass output, the optical bandpass filter having filtering characteristics defined by a filter profile, the filter profile including a high wavelength skirt at an upper wavelength region of the filter profile;
- a second monitor optically coupled to the output of optical bandpass filter, the second monitor generating a second electrical signal corresponding to the light emitted by the output of the bandpass filter;
- and
- a comparator receiving the first electrical signal and the second electrical signal, the comparator generating a dithering signal based on the first electrical signal and the second electrical signal, the dithering signal causing the directly modulated laser to emit the first optical signal at the wavelength proximate to the optical filter high wavelength skirt.
3 more elements
Dependencies are inferred from the claim text.