Method and arrangement for reducing spectral hole burning

Abstract

In one aspect, a WDM signal is assigned to a number of sub-bands with the channel spacing being correspondingly enlarged in each sub-band. The spectral hole burning is hereby essentially reduced, since this effect is restricted to the adjacent channels. The complete WDM signal is first pre-amplified before being divided into sub-bands.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is now described below in more detail with reference to examples, in which;

FIG. 1 shows the division of the C-band into four sub-bands FIG. 2 shows a first arrangement according to the invention,

FIG. 3 shows a cost-optimized arrangement and

FIG. 4 shows a further cost-optimized arrangement.

Claims

1.-14. (canceled)

15. A method for reducing spectral hole burning, comprising: dividing a plurality of channels of a WDM signal into a plurality of sub-bands such that the channels are assigned cyclically to each sub-band; andamplifying each of the sub-bands by a fiber amplifier.

16. The method as claimed in claim 15, wherein the assigning to the sub-bands is such that the channel spacing in the sub-bands amounts to 200 GHz.

17. The method as claimed in claim 15, further comprising amplifying the WDM signal in a closed state prior to the dividing.

18. The method as claimed in claim 15, further comprising combining the sub-bands to form an amplified WDM signal.

19. The method as claimed in claim 15, further comprising splitting the WDM signal into two signals having different frequency ranges, wherein the dividing is of at least one of the two split signals.

20. The method as claimed in claim 19, further comprising amplifying the WDM signal is in a closed state prior to the dividing.

21. The method as claimed in claim 19, further comprising combining the sub-bands to form an amplified WDM signal.

22. An arrangement for reducing spectral hole burning, comprising: a first de-interleaver to which a WDM signal having a plurality of channels is fed and that divides the channels into a plurality of sub-bands such that the channels are assigned cyclically to each sub-band; anda first plurality of booster amplifiers arranged such that each sub-channel is fed into one of the first plurality of amplifiers.

23. The arrangement as claimed in claim 22, wherein the de-interleaver is designed such that the channel spacing in each sub-band amounts to 200 GHz.

24. The arrangement as claimed in claim 22, further comprises a pre-amplifier arranged upstream of the de-interleaver in order to amplify the WDM signal.

25. The arrangement as claimed in claim 22, further comprises an interleaver or a combiner to combine to sub-bands to form an amplified WDM signal.

26. The arrangement as claimed in claim 22, further comprises an interleaver and a combiner to combine to sub-bands to form an amplified WDM signal.

27. The arrangement as claimed in claim 22, further comprises a band splitter that splits the WDM signal into a plurality of sub-bands including a first sub-band and a second sub-band,wherein the first sub-band is fed into the first de-interleaver and the second sub-band is fed to a further booster amplifier in a closed state.

28. The arrangement as claimed in claim 27, further comprises a pre-amplifier arranged upstream of the band splitter in order to amplify the WDM signal.

29. The arrangement as claimed in claim 22, further comprises:a band splitter that splits the WDM signal into a plurality of sub-bands including a first sub-band and a second sub-band,a second de-interleaver to which the second sub-band having a plurality of channels is fed and that divides the channels into a further plurality of sub-bands such that the channels are assigned cyclically to each further sub-band; anda second plurality of booster amplifiers arranged such that each further sub-channel is fed into one of the second plurality of amplifiers,wherein the first sub-band is fed into the first de-interleaver.

30. The arrangement as claimed in claim 29, further comprises a pre-amplifier arranged upstream of the band splitter in order to amplify the WDM signal.