Vibrational wavepacket motion in I2 excited with femtosecond laser pulses in the 200 nm wavelength region

Using 130 fs laser pulses with a photon energy of about 6.2 eV, vibrational wavepackets in high-lying electronic states of the iodine molecule are excited and observed by the pump–probe technique. The coherent vibrational motion with a frequency of about 60 cm−1 first experiences a collapse. Furthermore, two distinct revivals are observed attributed to the vibrational motion on the D(0u+) and, most probably, on the β(1g) ion-pair potential energy curves. The different behaviour of jet-cooled and warm molecules is discussed.