Patent ID: 6330375
Filing Date: 2001-12-11
Classification: H04B

Abstract:
A compensator for compensating for the effects of polarization mode dispersion occurring in an optical transmission fiber having principal states of polarization, the compensator comprisinga polarization transformation element operative for reorienting the polarization of particular components of an optical signal received over the optical transmission fiber,apparatus operative for dividing a signal coupled to an output of the polarization transformation element into a predetermined number of signals each having a polarization state oriented orthogonally to a respective one of the two principal states of polarization and for delaying each such divided signal a variable amount of time; andanalyzer means having an optical converter for converting a portion of a signal outputted by the apparatus into an electrical signal and having apparatus for splitting the converted signal into a plurality of signals and supplying the split signals to first, second and third analyzer sections, respectively, in which the first section operates to pass the entire spectrum of the outputted signal, the second section operates to pass only that portion of the entire spectrum that is below a predetermined frequency and the third section operates to pass a predetermined band of the entire spectrum, and wherein said distortion analyzer includes means for summing the outputs of the first and second sections and subtracting the output of the third section from the summed result to generate a distortion indicator and for supplying the distortion indicator to the polarization transformation element and said apparatus, and wherein said polarization transformation element and said apparatus, responsive to a change in the level of the distortion indicator, respectively changing until the level of the distortion indicator reaches a predetermined level, the orientation of each said polarization state and said variable amount of time.