Observation of wave packets with simultaneous electronic, vibrational, and rotational degrees of freedom in Li2

Using ultrafast pump-probe spectroscopy, we observe quantum beats between rovibrational states located on the uncoupled bound G(1)Pi(g)(divided by) and F(1)Sigma(g)(divided by) electronic curves of Li-2. From a pure launch state (A(1)Sigma(u)(+) v(A), J(A) = 11, 28), a wave packet is prepared using the output from a visible ultrafast optical parametric amplifier and is photoionized by an 800 nm ultrafast pulse. As the OPA wavelength is scanned, a vibrational progression of rotational quantum beats on the G curve is observed. At energies around 35000 cm(-1), in addition to rotational beats on the G curve, vibrational, rotational, and electronic beating between the G and F curves is observed. (C) 2004 Elsevier B.V. All rights reserved.