Wavelength converter and wavelength division multiplexing transmission method using same

A wavelength-division multiplexing transmission method using a wavelength converter, wherein a frequency interval of output lightwaves from said wavelength converter is reduced in comparison with WDM lightwaves inputted to said wavelength converter according to the following steps:

• (a) filtering out one or more clusters of lightwaves (sub-bands) in wavelength domains required to be wavelength converted by a broadband multi-channel simultaneous wavelength conversion portion according to (b) to (d) below from WDM lightwaves, by a dielectric multi-layered filter;
• (b) combining pump light with sub-bands filtered out by said dielectric multi-layered filter, by a first optical combiner;
• (c) generating wavelength converted sub-bands using four-wave mixing (FWM) of lightwaves output from said first optical combiner, by a nonlinear element;
• (d) filtering out wavelength converted sub-bands from lightwaves output from said nonlinear element, by an optical filter;
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• (e) combining output sub-bands of said optical filter with lightwaves not inputted to said broadband multi-channel simultaneous wavelength conversion portion by said dielectric multi-layered filter, by a second optical combiner.

A wavelength-division multiplexing transmission method using a wavelength converter, wherein a frequency interval of output lightwaves from said wavelength converter is broadened in comparison with WDM lightwaves inputted to said wavelength converter according to the following steps:

• (a) filtering out lightwaves in each M channels spacing (M is a positive integer) required to be wavelength converted by a first broadband multi-channel simultaneous wavelength conversion portion according to (b) to (d) below from WDM lightwaves, by a first optical filter;
• and
• (b) combining first pump light with lightwaves filtered out by said first optical filter, by a first optical combiner;
• and
• (c) generating wavelength converted lightwaves with the FWM from output lightwaves from said first optical combiner, by a first nonlinear element;
• and
• (d) filtering out wavelength converted lightwaves from output lightwaves of said first nonlinear element, by a second optical filter;
• and
• (e) filtering out lightwaves in each N channels spacing (N is a positive integer) required to be wavelength converted by a second broadband multi-channel simultaneous wavelength conversion portion according to (f) to (h) below from lightwaves not inputted to said first broadband multi-channel simultaneous wavelength conversion portion by said first optical filter, by a third optical filter;
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• (f) combining second pump light with lightwaves filtered out by said third optical filter, by a second optical combiner;
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• (g) generating wavelength converted lightwaves with the FWM from output lightwaves from said second optical combiner, by a second nonlinear element;
• and
• (h) filtering out wavelength converted lightwaves from output lightwaves of said second nonlinear element, by a fourth optical filter;
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• (i) combining output lightwaves from said fourth optical filter with lightwaves not inputted to said second broadband multi-channel simultaneous wavelength conversion portion by said third optical filter, by a third optical combiner;
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• (j) combining output lightwaves from said second optical filter with output lightwaves of said third optical combiner, by an optical wavelength combiner.