A polarization scrambler, and associated method for polarization scrambling, is provided wherein light is passed through a time-variant retarder. At least after upstream connection or downstream connection of a time-invariant retarder, this time-variant retarder may be represented as a retarder with eigen modes which are uniformly distributed on the Poincaré sphere and with a delay of 5π/6. An exemplary embodiment contains only two electro-optical wave plates, which are actuated by alternating signals containing harmonics. The polarization scrambler which is produced is independent of the input polarization of the light and can be used in devices for detection of polarization mode dispersion.