ULTRAFAST PHOTODISSOCIATION OF OCS AS STUDIED BY TUNABLE VUV-VUV PUMP-PROBE SPECTROSCOPY Ryuji Itakura, Akiyoshi Hishikawa, and Kaoru Yamanouchi Department of Chemisty, School of Science, University of Tokyo, Tokyo, Japan Jet-cooled OCS molecules were excited to the 21S+ state by tunable VUV laser light (154-150 nm). Using another tunable VUV laser light, the LIF spectra of the CO photofragments were measured and the vibrational and rotational distributions were derived to discuss the ultrafast photodissociation dynamics: OCS (21S+) -> CO(X1S+) + S(1S).