Atomic, Molecular, and Optical Physics Seminar
Strong Laser Field Excitation of Atoms and Molecules Through Quadratic Landau-Zener Crossings
Professor George N.
Department of Physics
University of Connecticut
I will discuss a novel mechanism (laser induced quadratic Landau-Zener crossings) for populating highly excited states of atoms and molecules with strong short-pulse laser fields. Fully correlated two-electron simulations of an ionized molecule in a strong laser field are presented which demonstrate the feasibility of this mechanism. Under certain conditions, 90% of the population is left in a single state roughly 20 eV above the ground state after the laser pulse with little ionization while the ground state is almost completely depopulated. This creates a prompt population inversion in the vacuum-ultraviolet spectral region. Moreover, during the laser pulse, transient population inversions occur at twice the excitation energy (~40 eV). Although these transient inversions exist only for about 1 femtosecond, they may be suitable for amplifying attosecond laser pulses created by high harmonic generation.
Monday, April 15, 2002
Gant Science Complex