  The dispersion scan (d-scan) technique is extended to measurement of the
timedependent polarization state of ultrashort laser pulses. In the simplest
implementation for linearly polarized ultrashort pulses, the d-scan technique
records the second harmonic generation (SHG) spectrum as a function of a known
spectral phase manipulation. By applying this method to two orthogonally
polarized projections of an arbitrary polarized electric field and by measuring
the spectrum at an intermediate angle, we can reconstruct the evolution over
time of the polarization state. We demonstrate the method by measuring a
polarization gate generated from 6 fs pulses with a combination of waveplates.
The measurements are compared to simulations, showing an excellent agreement.
