Speaker: Prof. Martin Aeschlimann, University of Kaiserslautern-Landau

Time: 9:00-11:00 a.m., October 12, 2023, GMT+8

Venue: School of Physics, Middle Building, Room 215

Abstract:

The transformation of light carrying spin angular momentum (SAM) into optical field vortices carrying orbital angular momentum (OAM) has been of great interest in recent years. The interaction between two optical fields, each carrying one of these degrees of freedom, and the transfer of the resulting angular momentum product to matter is rarely discussed. Here we measure the interaction between 3D light carrying axial SAM and 2D plasmon-polariton vortices carrying high-order transverse OAM. The interaction is mediated by two-photon absorption within a gold surface, and the resulting angular momentum mixing is imprinted into matter by excitation of electrons photo-emitted into the vacuum. In our approach, we follow the spatio-temporal dynamics of the plasmonic fields using time-resolved photoemission electron microscopy (TR-PEEM) with sub-femtosecond temporal resolution.

Biography:

Prof. Martin Aeschlimann is in Department of Physics and Research Center OPTIMAS, University of Kaiserslautern-Landau, Germany. He is currently the chair of Transregional Collaborative Research Center (SFB/TRR) 173 “Spin+X”, the head of Research Facility “Laboratory of Advanced Spin Engineering (LASE)”, and the chair of the State Research Center “Optics and Material Sciences (OPTIMAS)”. His research interest is devoted to the investigation of ultrafast phenomena in solids, thin films and nanoparticles. This includes the combination of short pulsed laser systems with surface science technology in order to develop novel methods for measuring ultrafast relaxation processes in real time with high temporal and spatial resolution. He has published more than 250 papers, including Nature, Science, Nature photonics, Nature Materials, Nature Physics, etc.

Source: School of Physics