a parallel monitored and controlled optical pmd compensator comprises a branch optical signal split from an optical signal path . a polarization controller and differential group delay are disposed in each of the paths . a controller adjusts polarization compensation of the pcs in response to pmd dispersion of the branch optical signal . a pmd monitor is preferably disposed in the branch path providing a monitor signal to the controller for use in adjusting the pcs . a polarization rotator may inject a reference signal into the paths with the pc disposed in the branch path acting as a polarization scrambler . a state of polarization of the reference signal may be monitored by polarimeters disposed in both paths and the sop of the reference signal in the branch path may be provided to the controller for adjusting polarization compensation of the inline pc .