Patent ID: 8442405

Claim:
A polarization mode dispersion compensator comprising: a first polarization controller that receives an optical signal that has travelled through an optical fiber, and adjusts the polarization of the optical signal; a tunable differential group delay element that receives the optical signal downstream of the first polarization controller, and adjusts the differential group delay of the optical signal; an optical parameter measurement mechanism that measures a degree of polarization of the optical signal downstream of the tunable differential group delay element; a first adjustment mechanism that controls the adjustment of the polarization provided by the first polarization controller and the adjustment of the differential group delay provided by the tunable differential group delay element in response to the measured degree of polarization, the first adjustment mechanism forming a portion of a first feedback loop and configured to control the first polarization controller and the tunable differential group delay element in a manner that reduces first order polarization mode dispersion of the optical signal; a second polarization controller that receives an optical signal downstream of the tunable differential group delay element, and further adjusts the polarization of the optical signal to have a polarization state that results in reduction in higher order polarization mode dispersion; and a second adjustment mechanism that controls the adjustment of the polarization provided by the second polarization controller in a manner that the optical signal converges on the polarization state that results in reduction in higher order polarization mode dispersion, the second adjustment mechanism forming a portion of a second feedback loop that is distinct from the first feedback loop.