Regensburg 2019 – wissenschaftliches Programm
O 64.5: Poster
Mittwoch, 3. April 2019, 17:45–20:00, Poster B1
Excitation Pathways in Nonlinear Photoemission visualized through Photon-Plasmon Spin-Orbit Mixing — •Michael Hartelt1, Grisha Spektor2, Eva Prinz1,3, Anna-Katharina Mahro1, Deirdre Kilbane1,4, Meir Orenstein2, and Martin Aeschlimann1 — 1Department of Physics and Research Center OPTIMAS, TU Kaiserslautern, Germany — 2Department of Electrical Engineering, Technion - Israel Institute of Technology, Haifa, Israel — 3Graduate School for Excellence Materials Science in Mainz, Germany — 4Telecommunications Software & Systems Group, Waterford Institute of Technology, Waterford, Ireland
Light carries spin angular momentum (SAM) in the form of its helicity, but it can also carry orbital angular momentum (OAM) in the form of vortex beams. This phenomenon was also shown for surface plasmon polaritons (SPP), where a phase vortex can be generated in 2D. We measured the interaction between light carrying axial SAM and plasmon vortices with high order transverse OAM.
The interaction is mediated via two-photon absorption on a gold surface, imprinting the resulting angular momentum mixing into matter by excitation of electrons that are photo-emitted into vacuum and detected by PEEM. We show that this interaction leads to both single and double photon-plasmon angular momentum mixing processes. The different mixing processes can be identified with specific quantum pathways of the electron excitation. In an interferometric pump-probe experiment, we isolate these pathways by frequency decomposition of the phase-resolved signal.