Arbitrary Control of Ultrafast Vectorial Electric-field Transient

The ability to tailor an ultrafast pulse at will has far-reaching impacts on numerous fields in modern science and technology. Here, we demonstrate simultaneous and independent control of the temporal and spatial degrees of freedom of an ultrabroad bandwidth, near-infrared femtosecond pulse using a single-layer dielectric metasurface. Exotic femtosecond pulses exhibiting a rich set of time-evolving instantaneous polarization states and structured wavefronts are both theoretically and experimentally demonstrated. Such an approach opens new possibilities in studying fundamental light-matter interactions at the femtosecond timescale and has the potential to enable applications in chiral spectroscopy, coherent control, and nonlinear optics.