Copropagating Raman pump unit to suppress four-wave mixing crosstalk between pump modes and WDM signals
AssigneeCisco Technology, Inc.
InventorsFausto Meli, Fabrizio Di Pasquale
Life of this patent
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Abstract
Four-wave mixing crosstalk between co-propagating Raman amplification pump sources and WDM channels is suppressed. Therefore, co-propagating pumping may be applied to Raman amplification without incurring penalties due to four-wave mixing crosstalk. Pump power need not be substantially increased to accommodate use of the present invention. Also, the use of lower cost Fabry-Perot pump sources is facilitated. In one implementation, the advantageous suppression of four-wave mixing crosstalk between pump signals and WDM channels is accomplished by imposing chromatic dispersion on the co-propagating pump sources.
Claims24
A method for operating a Raman pump unit to suppress four-wave mixing interaction between pump modes and data signals, said method comprising:
- generating a pump signal;
- and
- applying a wavelength-dependent phase shift to said pump signal.
A Raman pump unit comprising:
- a pump signal source that outputs a pump signal;
- and
- a dispersion application unit that introduces a frequency-dependent phase shift to said pump signal.
A Raman amplification system comprising:
- a Raman pump unit comprising:
- a pump signal source that outputs a pump signal;
- and
- a dispersion application unit that introduces a frequency-dependent phase shift to said pump signal;
- and
- a fiber into which said pump signal is injected in a direction of propagation of a signal to be amplified.
Apparatus for operating a Raman pump unit to suppress four-wave mixing interaction between pump modes and data signals, said method comprising:
- means for generating a pump signal;
- and
- means for applying a wavelength-dependent phase shift to said pump signal.
Dependencies are inferred from the claim text.