To overcome the challenges of ancillae preparation in two-dimensional spectrally sheared
interferometry, we apply the approach based on spectral filtering in the Fourier plane of a 4-f
zero-dispersion compressor, which allows the generation of two sheared and synchronized
monochromatic fields. The scheme provides direct and precise measurement of their
spectral shear, greatly improving the accuracy and reliability of spectral phase retrieval. By
characterizing few-optical-cycle pulses spanning nearly two octaves of bandwidth, we prove …

We introduce a scheme to overcome the challenges of ancillae preparation in traditional
spectrally-sheared interferometry techniques for pulse characterization. The approach,
applied to two-dimensional spectral shearing interferometry, reliably characterizes few-
optical-cycle pulses from UV to IR.