Granted Patent B2

US 6,906,804 · App. 10/320,065 · Granted Jun 14, 2005

Abstract

Claims (47)

1. A method, comprising;

combining portions of each of a plurality of optical signals with a reference optical signal to produce a combined optical signal, each of said plurality of optical signals having a respective wavelength;

determining, using beat frequencies associated with said combined optical signal, a spectral offset between at least one of said plurality of optical signals and said reference optical signal; and

adapting said at least one optical signal in response to said determined spectral offset.

2. The method of claim 1 , wherein each of said optical signals is generated by a respective optical source, and said step of adapting comprises:

adapting the operation of at least one of said optical sources to effect an adaptation in the corresponding at least one optical signal.

3. The method of claim 1 , wherein said step of adapting comprises at least one of changing a phase parameter, changing a frequency parameter and changing an amplitude parameter of said at least one optical signal.

4. The method of claim 1 , further comprising:

modulating at least one of said plurality of optical signals according to a respective code word;

said step of determining including identifying an optical signal contributor to a beat frequency by detecting a corresponding modulated code word.

5. The method of claim 1 , wherein said reference optical signal comprises one of a continuous wave optical signal, a pulsed optical signal and a multiple frequency optical signal.

6. The method of claim 1 , further comprising:

determining operating parameters associated with at least one of a plurality of optical channels supporting said optical signals;

wherein at least some of said determined operating parameters are used to adapt said at least one optical signal.

7. The method of claim 1 , further comprising:

adapting at least one additional optical signal in response to said determined spectral offset.

8. The method of claim 7 , further comprising:

determining operating parameters associated with at least one of a plurality of optical channels supporting said optical signals;

wherein at least some of said determined operating parameters are used to adapt said at least one additional optical signal.

9. The method of claim 1 , wherein said step of determining comprises comparing a spectral parameter of said combined optical signal to a spectral profile to identify thereby spectral deviations.

10. The method of claim 1 , wherein said step of determining comprises comparing a power parameter of said combined optical signal to a power profile to identify thereby spectral deviations.

11. Apparatus, comprising:

a plurality of transmitters, each of said transmitters comprising an optical source producing an optical signal at a respective wavelength;

a combiner, for combining a reference signal and a portion of each of said optical signals to produce a combined optical signal; and

at least one optical detector, for detecting beat frequencies associated with said combined optical signal, said beat frequencies indicative of a spectral offset between said optical signals and said reference optical signal; and

a controller, responsive to said at least one optical detector, for adapting the operation of at least one of said transmitters to modify thereby the spectral offset between a corresponding optical signal and an adjoining optical signal.

12. The apparatus of claim 11 , further comprising:

a plurality of splitters, for directing said portion of each of said modulated optical signals to said combiner.

13. The apparatus of claim 11 , further comprising:

a multiplexer, for multiplexing said optical signals to produce an output signal; and

a channel power monitor, for measuring a portion of said output signal to determine thereby an output signal power level;

said controller being responsive to said channel power monitor for adapting the operation of at least one of said transmitters.

14. The apparatus of claim 11 , wherein each of said transmitters further comprises:

a modulator, for modulating the respective optical signal produced by the transmitter.

15. The apparatus of claim 14 , wherein:

at least one of said modulators operates to modulate its respective optical signal according to a respective code word;

said controller identifying said modulated code word to identify the source of spectral contributions to said combined optical signal.

16. The apparatus of claim 14 , wherein:

at least one of said modulators operates to modulate its respective optical signal according to a respective code word;

said controller identifying said modulated code word to identify the source of spectral contributions to said combined optical signal.

17. The apparatus of claim 16 , wherein said controller identifies said at least one code word modulated optical signal using correlation.

18. The apparatus of claim 11 , wherein at least a spectral parameter of said beat frequencies are compared to a spectral profile to identify thereby spectral deviations.

19. The apparatus of claim 11 , wherein at least a power parameter of said beat frequencies are compared to a power profile to identify thereby spectral deviations.

20. Apparatus, comprising:

a combiner, for combining portions of each of at least one optical signal with a reference optical signal to produce a combined optical signal; and

a signal processor, for measuring beat frequencies associated with said combined optical signal and determining therefrom a spectral offset between said at least one optical signal and said reference optical signal;

said signal processor communicating toward an optical signal source indicia of said determined spectral offset such that spectral adaptations may be effected in a closed loop manner.

Assignments (9)