Observation of the K2 43Δg state by cw perturbation-facilitated optical-optical double resonance spectroscopy

This paper reports for the first time both, an experimental observation and theoretical calculations of the K-2 4(3)Delta(g) state. For the experiment we used cw perturbation-facilitated optical-optical double resonance (PFOODR) spectroscopy. A single mode Ti-sapphire laser and a dye laser served as the pump and probe lasers respectively. A total of 55 PFOODR signals have been assigned to the 4(3)Delta(g) <-- b(3)Pi(u) transitions. Absolute vibrational numbering was determined by using quantum defect analysis combined with comparing observed intensities with calculated Franck-Condon factors (FCF). For the former we used known parameters from the 2(3)Delta(g) state since the 2(3)Delta(g) and the 4(3)Delta(g) states belong to the same Rydberg series. We report here our experimental and calculated spectroscopic constants, the corresponding RKR potential energy curve, the Franck-Condon table for the 4(3)Delta(g) <----> b(3)Pi(u) system, as well as a comparison with the theoretical potential energy curve. The T-e value is found to be 28408.938(52)cm(-1). (C) 2003 Elsevier Science (USA). All rights reserved.