Synthesis of ultrafast wavepackets with tailored spatiotemporal properties

Sculpting light in space and time can provide unprecedented opportunities in many areas of science and technology, ranging from extreme nonlinear optics and quantum networks to new families of ultrafast fibre amplifiers. Although endeavours in accessing the light’s temporal and spatial degrees of freedom have been carried out, controlling the electromagnetic field in its entirety has always been a major challenge. Here we demonstrate a versatile approach to synthesize convoluted ultrafast light structures in which the spatial and temporal dimensions are precisely correlated. By utilizing a two-stage reconfigurable module, we produce separable and non-separable trains of ultrafast wavepackets with time-varying dynamic angular momentum and tailored spectral characteristics. The generated light states are observed using mode- and frequency-resolved tomographic methodologies capable of reconstructing their complex field structure in space and time. Our results could have ramifications in a broad range of applications such as high-resolution microscopy, high-harmonic generation and laser micromachining.