  The use of structured ultrashort pulses with coupled spatiotemporal
properties is emerging as a key tool for ultrafast manipulation. Ultrafast
vector beams are opening exciting opportunities in different fields such as
microscopy, time-resolved imaging, nonlinear optics, particle acceleration or
attosecond science. Here, we implement a technique for the full
characterization of structured time-dependent polarization light waveforms with
spatiotemporal resolution, using a compact twofold spectral interferometer,
based on in-line bulk interferometry and fibre-optic coupler assisted
interferometry. We measure structured infrared femtosecond vector beams,
including radially polarized beams and complex-shaped beams exhibiting both
temporal and spatial evolving polarization. Our measurements confirm that light
waveforms with polarization evolving at the micrometer and femtosecond scales
can be achieved through the use of structured waveplates and polarization
gates. This new scale of measurement achieved will open the way to predict,
check and optimize applications of structured vector beams at the femtosecond
and micrometer scales.
