Berlin 2005 – wissenschaftliches Programm

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Q: Quantenoptik und Photonik

Q 21: Poster Quanteneffekte

Q 21.2: Poster

Montag, 7. März 2005, 11:00–12:30, Poster HU

Coherent Population Transfer via the Ionization Continuum in Helium — •Thorsten Peters¹, Leonid Yatsenko², Klaas Bergmann¹, and Thomas Halfmann¹ — ¹Fachbereich Physik, TU Kaiserslautern, 67663 Kaiserslautern, Germany — ²Institute of Physics, Ukrainian Academy of Sciences, prospect Nauki 46, Kiev-22, 03650, Ukraine

Coherent population transfer by stimulated Raman adiabatic passage (STIRAP) in a Λ - type level system of purely bound states is a well established technique. It has long been proposed to apply similar coupling schemes also to systems involving continuum states, i.e. to transfer population from a (bound) ground to a (bound) target state via an ionization or dissociation continuum. The effect is closely related to laser-induced continuum structures (LICS), which permit the laser-based manipulation of photofragmentation processes, but do not mediate population transfer via the continuum.

We present first experimental results, which clearly demonstrate coherent transfer of population in a STIRAP-like pulse sequence via the ionization continuum in Helium. The experimental data are compared to numerical simulations, based on a density matrix approach including ab-initio calculated atomic parameters.