Fig. 4.

Phase control of FEWPs from bichromatic MPI with CRCP and COCP (3ω:4ω) pulses. Energy-calibrated central x-y-sections of the reconstructed PMDs for different values of the CEP φ_ce and the relative phase φ₂ in cartesian (upper panels) and polar (lower panels) representation. Zero phase results from Fig. 3 are shown in a, d for comparison. b Variation of the CEP to φ_ce = π rotates the propeller-type CRCP field (see inset) and the corresponding FEWP by ${\alpha }_0^{\mathrm{cr}}=\pi \mathrm{∕}7$ about the laser propagation direction. The same rotation, albeit in opposite direction, is induced by the relative phase φ₂ = π/3 of the blue field, leading to the same shape of field and FEWP in c. In the COCP case, a CEP variation to φ_ce = π rotates the heart-shaped pulse by ${\alpha }_0^{\mathrm{co}}=\pi$. The crescent-shaped FEWP follows the field rotation, as shown in e. f An equivalent rotation in opposite direction is induced by the relative phase of φ₂ = π/3. The center of the azimuthal lobes, indicated by vertical lines in the bottom frames, were derived from sinusoidal fits presented in Supplementary Note 3