System for higher-order dispersion compensation including a delay line

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.

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.

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.