FEMTOSECOND VIBRATIONAL WAVEPACKET SPECTROSCOPY IN THE ELECTRONIC GROUND-STATE OF K-2

Vibrational wavepacket propagation in the electronic ground state \X] of supersonic jet cooled potassium dimers was investigated with a femt osecond pump-probe experiment. The wavepackets were generated by reson ance enhanced stimulated Raman scattering into upsilon(X)(-n) = 5 and interrogated by a time delayed three photon ionization process. The ch oice of the wavelength of the probe photons enabled a pure detection o f ground state wavepacket dynamics. Fourier analysis of the wavepacket oscillation with a period of 375 fs reveals a one color stimulated em ission pumped component around 92 cm(-1) and a stimulated Raman pumped component around 88 cm(-1). (C) 1998 Elsevier Science B.V.