Berlin 2012 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 34: Poster Session I (Graphene; Plasmonics and nanooptics; Coherence and coherent control in nanophotonics and plasmonics)

O 34.59: Poster

Dienstag, 27. März 2012, 18:15–21:45, Poster E

Coherent Control of the Electron Emission from Metal Nanotips due to Ultrashort Laser Pulses — •Steve Lenk and Erich Runge — Institut für Physik und Institut für Mikro- und Nanotechnologien, Technische Universität Ilmenau, 98693 Ilmenau, Germany

Recent experiments show the possibility for a novel scanning microscope using ultrafast laser-induced photoelectron emission. The analysis of the experimental data requires a detailed theoretical knowledge of the emission process and the underlying physics. We investigate the electron emission from sharp gold nanotips illuminated by ultrashort femtosecond laser pulses theoretically. The emission processes under discussion for few-femtosecond laser pulses are multiphoton emission and optical field emission. We calculate the probability current and the Wigner distribution of the emitted electrons from a numerical solution of the time-dependent Schrödinger equation via a real-space product-formula algorithm. By the use of an optimization routine, we study the dependence of several target functions, like the emission current, on laser pulse properties and on confined potential energy profiles. By comparing experimental and theoretical findings, we can distinguish the dominant physical processes for different energy profiles and pulse shapes. Generally speaking, such investigation allow us to find optimized laser pulse properties to achieve the best electron emission characteristics for different experimental requirements.