Spectrally resolved wedged reversal shearing interferometer.

In this Letter, we introduce a technique to fully determine the spatio-temporal electric field (,,) of an arbitrary ultrashort pulse. By passing the beam through a wedged reversal shearing interferometer followed by a scanning Michelson interferometer, the field autocorrelation of the shearing interferograms is measured. The spectrum of the shearing interferograms is obtained after a Fourier transform by the Whittaker-Shannon sampling theorem, yielding the amplitude and wavefront information at every wavelength. With the addition of the phase information of a single point, we are able to directly reconstruct the spatio-temporal electric field (,,) of an arbitrary ultrashort pulse.