Similarly, to light holography, ultrafast photoelectron holography makes use of a probe and a reference wave to reconstruct a target using phase differences. This makes use of the fact that different pathways for an electron in a strong laser field may be associated with specific interference patterns. Typically, the reference is a direct pathway and the probe is associated to a laser-induced rescattering process. If traditional orbit-based approaches are employed, such as the strong-field approximation, for linearly polarized fields rescattering will occur near and on the polarization axis. This will make it detrimental for probing targets whose geometry is oriented perpendicular to the field. In the present contribution, we employ a novel approach which goes beyond that and takes into account the residual binding potential and the external laser field on equal footing: The Coulomb Quantum Orbit Strong-Field Approximation (CQSFA).
By studying a variety of atomic species prepared in excited states of different geometries, we show that, due to the presence of the Coulomb potential, rescattering will no longer be confined to this axis, which makes it possible to probe orbitals whose polarization is perpendicular to that of the field. We also identify the main types of orbits responsible for a non-vanishing photoelectron signal within the CQSFA and initial momentum distributions of the instances of tunnelling and re-scattering as well as assess the orbits geometries. We further probe the interplay between the driving field and the binding potential by modifying parameters such as the field intensity and the binding energy.
Link to the talk will be on our Moodle Page – See you then!