Stuttgart 2012 – scientific programme

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Q: Fachverband Quantenoptik und Photonik

Q 54: Poster 3

Q 54.33: Poster

Thursday, March 15, 2012, 16:30–19:00, Poster.I+II

Ultrafast electron emission from sharp tungsten tips using few-cycle infrared pulses — •Michael Förster, Sebastian Thomas, Markus Schenk, Michael Krüger, Lothar Maisenbacher, and Peter Hommelhoff — Max-Planck-Institut für Quantenoptik, Hans-Kopfermann-Straße 1, 85748 Garching bei München, Germany

Strong-field photoemission from metal nanotips triggered by few-cycle Ti:Sa pulses shows pronounced similarity to the well-studied case of gases irradiated with high-power lasers. In particular, evidence for the recollision of electrons with the surface of a tungsten tip has been found [1], which hints at the possibility of electron recombination with the metal and corresponding high harmonic generation (HHG).

Using longer wavelengths offers the possibility to access a new parameter range that is in principle similar to that leading to HHG in gas systems, but comes at the difficulty that no known laser medium supports few-cycle pulses around 2 µm directly. Here we show first results of photoemission measurements using two different light sources, one of them relying on parametric amplification and broadband difference-frequency generation [2]. We compare our findings to established results in the solid state and the gas phase.

[1] M.Krüger, M.Schenk, P.Hommelhoff, Nature 475, 79 (2011).

[2] C.Homann, M.Bradler, M.Förster, P.Hommelhoff, E.Riedle,

    submitted for publication.