Determination of Electron Band Structure using Temporal Interferometry

We propose an all-optical method to directly reconstruct the band structure of semiconductors. Our scheme is based on the temporal Young’s interferometer realized by high harmonic generation (HHG) with a few-cycle laser pulse. As a time-energy domain interferometric device, temporal interferometer encodes the band structure into the fringe in the energy domain. The relation between the band structure and the emitted harmonic frequencies is established. This enables us to retrieve the band structure from the HHG spectrum with a single-shot measurement. Our scheme paves the way to study matters under ambient conditions and to track the ultrafast modification of band structures.