Affiliation: | a Institut für Physik der Humboldt-Universität, Arbeitsgruppe “Nichtklassische Strahlung”, Rudower Chaussee 5, D-12484 Berlin, Germany b Max-Born Institut für Nichtlineare Optik und Kurzzeitspektroskopie, Rudower Chaussee 6, D-12484 Berlin, Germany c Dipartimento di Fisica ‘Alessandro Volta' dell'Universitá degli Studi di Pavia, Istituto Nazionale di Fisica della Materia, Unitá di Pavia, via Bassi 6, I-27100 Pavia, Italy d Institute of Spectroscopy, Russian Academy of Sciences, Troitsk 142092, Moscow Region, Russia e Department of Chemistry, Princeton University, Frick Chemical Laboratory, Washington Road and William Street, Princeton, NJ 08544, USA |