Patent ID: 6748126
Filing Date: 2004-06-08
Classification: G02B,H04B

Abstract:
An adaptive polarization mode dispersion compensator comprisinga. 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 polarization delay unit optically coupled to receive the controller output signal from the polarization controller, the differential polarization delay unit including: i. a polarization beam splitter element having a first 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 birefringent optical waveguide optically coupled and aligned to the first output port, the first optical waveguide having a first chirped grating to reflect the first polarization signal and having a first reference reflection point; iii. a second birefringent optical waveguide optically coupled and aligned to the second output port, the second optical waveguide having a second chirped grating to reflect the second polarization signal and having a second reference reflection point; iv. at least one tuning mechanism coupled to at least one of the gratings, wherein the tuning mechanism variably adjusts one of the reference reflection points with respect to the other reference reflection point; v. a combiner element that recombines the two reflected orthogonal polarization signals into a delay line output; c. a signal quality analyzer optically coupled to sample the differential polarization delay unit output, wherein the analyzer evaluates the quality of the differential polarization delay unit output signal and provides a control signal to the polarization controller and the differential polarization delay unit.