  A method for time differentiation based on a Babinet-Soleil-Bravais
compensator is introduced. The complex transfer function of the device is
measured using polarization spectral interferometry. Time differentiation of
both the pulse field and pulse envelope are demonstrated over a spectral width
of about 100 THz with a measured overlap with the objective mode greater than
99.8%. This pulse shaping technique is shown to be perfectly suited to time
metrology at the quantum limit.
