非表示:
キーワード:
-
要旨:
In this thesis, the ionization of atoms and small molecules in strong laser
fields is experimentally studied by utilization of a reaction microscope.
The fundamental process of tunnel ionization in strong laser fields is subject of
investigation in a pump-probe experiment with ultrashort laser pulses. A coherent
superposition of electronic states in singly charged argon ions is created within the
first, and subsequently tunnel-ionized with the second pulse. This gives access to
state-selective information about the tunneling process and allows to test common
models.
Moreover, the ionization of krypton and argon at different wavelengths is studied,
from the multiphoton to the tunneling regime. The population of autoionizing doubly
excited states in the laser fields is proven and a possible connection to the wellknown
dielectronic recombination processes is discussed. The wavelength-dependent
investigations are furthermore extended to molecular hydrogen. In addition to ionization,
this system might undergo different dissociative processes. Channel-selective
electron momentum distributions are presented and compared to each other.
