Pattern recognition and optimization in strong-field photoelectron holography

• Applicant: Nikolay Shvetsov-Shilovskiy, Ph.D.
• Subject Area: Optics, Quantum Optics and Physics of Atoms, Molecules and Plasmas
• Term: since 2016
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 336041027

Strong-field photoelectron holography (SFPH) is a rapidly developing method aiming at visualization of electronic and molecular dynamics in real time. SFPH implements the concept of holography in strong-field physics. The hologram that can be recorded in a table-top experiment is created by the interference of freed electrons that are driven back by the laser field to their parent ions with those that reach the detector without rescattering. This hologram in the electron momentum distribution contains extensive time-resolved information both about the molecular ion and the scattered electron. Although initially the actual implementation of SFPH was restricted to static systems, the method has recently been applied to study of nuclei and electron dynamics. The retrieval of the information encoded in the experimental holographic structures requires careful theoretical analysis. The main objective of this project is to develop a theoretical method capable of extracting the time-resolved information about the nuclear dynamics from the electron momentum distributions. This information will be obtained as a result of an optimization procedure that treats the experimental photoelectron momentum distribution as a target that is to be achieved. We shall compare electron momentum distributions calculated in the optimization process using the tools of pattern recognition and image analysis. Furthermore, we optimize the shape of the laser pulse in order to enhance the interference structures that provide the most valuable information about the molecule under study. Since electron momentum distributions are used also in the laser-induced electron diffraction technique, the anticipated outcome of the project is important for the whole field of time-resolved molecular imaging.

• DFG Programme: Research Grants
• International Connection: Denmark
• Co-Investigator: Professor Dr. Manfred Lein
• Cooperation Partner: Professor Dr. Lars Bojer Madsen