PUB - Publikationen an der Universität Bielefeld

Using leading order intense-field S-matrix analysis, we study the angular and energy distribution of the photoelectron for multiphoton ionization of diatomic molecules and linear carbon clusters. We show that alignment of molecules can be simply determined from the observation (i) of a nodal minimum along the laser polarization direction in the photoelectron angular distributions for molecules with active pi electrons or (ii) of a minimum in the above threshold ionization spectra of homonuclear diatomics at high energies. The origins, as well as the conditions under which these signatures can be observed in the experiment, are discussed.