Claims
- 1. A higher-order dispersion compensator for tuning a polarization controlled signal having a first polarization mode dispersion component, a second order polarization mode dispersion component, and a variable chromatic dispersion component, the compensator comprising:
a) a first tuning element that adjusts the first order polarization mode dispersion component of the polarization controlled signal; and b) a second tuning element that adjusts the second order polarization mode dispersion component and the variable chromatic dispersion component of the polarization controlled signal.
- 2. The compensator of claim 1, wherein the first tuning element and the second tuning element comprise:
a) a polarization beam splitter coupled to receive the polarization controlled signal, where the polarization beam splitter splits the polarization controlled signal into a first polarization component and a second orthogonal polarization component; b) a first waveguide optically coupled to receive the first polarization signal, the first waveguide having a first non-linearly chirped grating tuned to reflect the first polarization signal and having a first reference reflection point; c) a second waveguide optically coupled to receive the second polarization signal, the second waveguide having a second non-linearly chirped grating tuned to reflect the second polarization signal and having a second reference reflection point; d) a first tuning mechanism that tunes both the first and the second grating simultaneously; and e) a second tuning mechanism that tunes the second grating independently of the first grating.
- 3. The compensator of claim 2, the polarization controlled signal further comprising a static chromatic dispersion component, the compensator comprising a static chromatic dispersion compensation element, wherein the average chirp rate of the first and second gratings correspond to the amount of fixed chromatic dispersion to be compensated.
- 4. The compensator of claim 2, wherein the first order polarization mode dispersion compensation element includes the second tuning mechanism and the second grating and the first order polarization mode dispersion compensation is achieved by tuning the second non-linearly chirped grating separately from the first grating.
- 5. The compensator of claim 2, wherein the second order polarization mode dispersion compensation and variable chromatic dispersion compensation elements include the first and second grating and the first tuning mechanism and variable chromatic dispersion compensation and higher-order polarization mode dispersion compensation are achieved by tuning the first and second gratings in unison.
- 6. The compensator of claim 2, wherein the compensator is an adaptive compensator further including a signal analyzer, which provides control signals to at least one of the tuning mechanisms.
- 7. The dispersion compensator of claim 2, wherein the waveguides are optical fibers.
- 8. The dispersion compensator of claim 2, wherein the waveguides are optical single-mode polarization-maintaining fibers.
- 9. The dispersion compensator of claim 2, wherein the waveguides are optical single-mode polarizing fibers.
- 10. The dispersion compensator of claim 2, wherein the waveguides are shaped optical fibers.
- 11. The dispersion compensator of claim 2, where the gratings are fiber Bragg gratings.
- 12. The dispersion compensator of claim 2, where the dispersion compensator is at least partially integrated into an integrated optical chip.
- 13. The dispersion compensator of claim 2, wherein the waveguides are channel waveguides in an integrated optical chip.
- 14. The dispersion compensator of claim 13, where the integrated optical chip is a lithium niobate chip.
- 15. The dispersion compensator of claim 2, wherein the splitter is a splitter/combiner element that also recombines the reflected first and second polarization components.
- 16. The dispersion compensator of claim 2, wherein the first grating and the second grating both have substantially the same reflection profiles and substantially the same chirp rates; and the first and second reference reflection points are at substantially the same optical path length.
- 17. The dispersion compensator of claim 2, where prior to adjustment by the tuning mechanism, the first reflection point of the first grating is at a shorter optical path length from the split point than the second reflection point.
- 18. The dispersion compensator of claim 2, wherein the tuning mechanism mechanically stresses the gratings.
- 19. The dispersion compensator of claim 2, the tuning mechanism comprising mechanisms that tune the gratings acoustically, thermally, electro-optically, or mechanically.
- 20. The dispersion compensator of claim 2, wherein the first and second gratings measure at least one meter.
- 21. A higher order compensator for tuning a signal of arbitrary polarization, the compensator comprising
a) a polarization controller that converts incoming light of an arbitrary polarization to a polarization controlled signal having a desired state of polarization; and b) the compensator of claim 2.
- 22. An adaptive higher-order dispersion compensator comprising:
a) a polarization controller that converts incoming light of an arbitrary polarization to a polarization controlled signal having a desired state of polarization; b) a differential higher-order delay line optically coupled to receive the polarization controlled signal, the delay line including:
i) a polarization beam splitter coupled to receive the polarization controlled signal, where the polarization beam splitter splits the polarization controlled signal into a first polarization signal and a second orthogonal polarization signal, ii) a first optical fiber non-linearly chirped Bragg grating coupled to receive the first polarization signal, iii) a second optical fiber non-linearly chirped Bragg grating coupled to receive the second polarization signal, iv) a first tuning mechanism that independently tunes the first grating, v) a second tuning mechanism that tunes both gratings in unison, and vi) a combiner element that recombines the two reflected orthogonal polarization signals into a delay line output; and c) a signal analyzer optically coupled to sample the delay line output, wherein the analyzer evaluates the delay line output signal and controls the polarization controller and the tuning mechanisms.
- 23. An adaptive higher-order dispersion compensator comprising:
a) a polarization controller that converts incoming light of an arbitrary polarization to a controller output signal having a desired state of polarization; b) a differential higher-order delay line optically coupled to receive the controller output signal from the polarization controller, the delay line including:
i) a polarization beam splitter element having an input port coupled to receive the controller output signal, a split point, a first and a second output port, where at the split point the controller output signal is split into a first and a second orthogonal polarization signal, the first and the second polarization signal being directed to the first and second output ports respectively, ii) a first waveguide optically coupled and aligned to the first output port, the first waveguide having a first non-linearly chirped grating tuned to reflect the first polarization signal and having a first reference reflection point, iii) a second waveguide optically coupled and aligned to the second output port, the second waveguide having a second non-linearly chirped grating tuned to reflect the second polarization signal and having a second reference reflection point, iv) a first tuning mechanism comprising first and second tuning devices coupled to both the first and second gratings, where the tuning devices tune both gratings a substantially equal amount, v) a second tuning mechanism comprising a second tuning device, where the second tuning device independently tunes only one of the gratings, vi) a combiner element that recombines the two reflected orthogonal polarization signals into a delay line output; and c) a signal quality analyzer optically coupled to sample the delay line output, wherein the analyzer evaluates the quality of the delay line output signal and provides a control signal to the polarization controller and the differential delay line.
- 24. A higher-order dispersion compensator for tuning a polarization controlled signal having a first polarization mode dispersion component, a second order polarization mode dispersion component, and a variable chromatic dispersion component, the compensator comprising:
a) a polarization beam splitter coupled to receive the polarization controlled signal, where the polarization beam splitter splits the polarization controlled signal into a first polarization component and a second orthogonal polarization component; b) a first waveguide optically coupled to receive the first polarization signal, the first waveguide having a first non-linearly chirped grating tuned to reflect the first polarization signal and having a first reference reflection point; c) a second waveguide optically coupled to receive the second polarization signal, the second waveguide having a second non-linearly chirped grating tuned to reflect the second polarization signal and having a second reference reflection point; d) a first tuning mechanism that tunes both the first and the second grating simultaneously; and e) a second tuning mechanism that tunes the second grating independently of the first grating.
RELATED APPLICATIONS
[0001] The present application is related to and claims priority from the co-pending, commonly assigned U.S. applications entitled, “System for Polarization Mode Dispersion Compensation”, U.S. PTO Ser. No. 10/036,987, and “Method for Polarization Mode Dispersion Compensation”, U.S. PTO Ser. No. 10/037,024, both of which are incorporated by reference. This application also is related to and claims priority from provisional application “Method And System For Higher Order Dispersion Compensation”, U.S. PTO serial No. 60/344,965, which also is hereby incorporated by reference.
Provisional Applications (1)
|
Number |
Date |
Country |
|
60344965 |
Dec 2001 |
US |