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US 6,476,953 B1Granted
Wavelength preserving regenerator for DWDM transmission systems
AssigneeFujitsu Network Communications, Inc.
InventorPaul R. Morkel
Life of this patent
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Abstract
An optical system includes a number of substantially identical, tunable, wavelength-preserving, optical regenerators 10. Each of the regenerators 10 is tuned to a different wavelength so that when a regenerator 10 is tuned to a given wavelength that regenerator will generate a regenerated, reshaped and retimed optical signal at the same given wavelength. The system also includes a multiplexer 32 coupled to receive and combine regenerated optical signal from each of regenerators. A filtering system (34) is provided, either internal or external to regenerators 10, to demultiplex different wavelength signals from an aggregate WDM optical signal.
Claims24
A wavelength preserving optical regenerator comprising:
- an optical-to-electrical conversion unit with an input to receive an optical signal at a first wavelength;
- a retiming and regeneration circuit with an input coupled to an output of the optical-to-electrical conversion unit;
- an electrical-to-optical conversion unit with an input coupled to an output of the retiming and regeneration circuit, the electrical-to-optical conversion unit operable to receive an electrical signal and generate an optical signal based on the electrical signal, the electrical-to-optical conversion unit including a tunable laser that can be tuned so that the wavelength of the optical signal generated by the electrical-to-optical conversion unit has a fixed relationship with the first wavelength;
- and
- an optical monitor including a first optical input coupled to the input of the optical-to-electrical conversion unit and a second optical input coupled to an output of the electrical-to-optical conversion unit, the optical monitor further comprising a control output coupled to the electrical-to-optical conversion unit such that a signal output from the control output can be used to tune the wavelength of the optical signal generated by the electrical-to-optical conversion unit.
2 more elements
A method of regenerating a digital optical signal, the method comprising:
- providing a regenerator that includes a tunable light source;
- tuning the light source to a first wavelength;
- receiving an optical signal at the first wavelength;
- converting the optical signal into an electrical signal;
- regenerating the electrical signal;
- converting the regenerated electrical signal to an optical signal at the first wavelength, the optical signal being generated by the tunable light source;
- comparing the optical signal received at the first wavelength and the optical signal being generated by the tunable light source;
- and
- generating a control signal based on the comparison, the control signal controlling the tuning of the light source to the first wavelength.
6 more elements
An optical system comprising:
- a plurality of substantially identical, tunable, wavelength-preserving, optical regenerators, each of the regenerators tuned to a different wavelength such that when the regenerator is tuned to a given wavelength the regenerator will generate a regenerated, reshaped and retimed optical signal at that given wavelength;
- a multiplexer coupled to receive and combine regenerated optical signals from each of the regenerators;
- and
- an optical switch fabric coupled between the regenerators and the multiplexer.
1 more element
An optical system comprising:
- a plurality of substantially identical, tunable, wavelength-preserving optical regenerators, each of the regenerators tuned to a different wavelength such that when the regenerator is tuned to a given wavelength, the regenerator will generate a regenerated, reshaped and retimed optical signal at that given wavelength, wherein each of the optical regenerators comprises:
- an optical-to-electrical conversion unit with an input to receive an optical signal at the given wavelength;
- a retiming and regeneration circuit with an input coupled to an output of the optical-to-electrical conversion unit;
- an electrical-to-optical conversion unit with an input coupled to an output of the retiming and regeneration circuit, the electrical-to-optical conversion unit operable to receive an electrical signal and generate an optical signal based on the electrical signal, the electrical-to-optical conversion unit including a tunable laser that is tuned so that the wavelength of the optical signal generated by the electrical-to-optical conversion unit is the same as the given wavelength;
- and
- an optical monitor including a first optical input coupled to the input of the optical-to-electrical conversion unit and a second optical input coupled to an output of the electrical-to-optical conversion unit, the optical monitor further comprising a control output coupled to the electrical-to-optical conversion unit such that a signal output from the control output can be used to tune the wavelength of the optical signal generated by the electrical-to-optical conversion unit;
- and
- a multiplexer coupled to receive and combine regenerated optical signals from each of the regenerators.
5 more elements
Dependencies are inferred from the claim text.