FEMTOSECOND RAMAN-INDUCED POLARIZATION SPECTROSCOPY STUDIES OF ROTATIONAL COHERENCE IN O2, N2 AND CO2

Using the femtosecond Raman-induced polarization spectroscopy (RIPS) t echnique, we have observed ground vibronic state rotational coherence in gaseous N2, CO2 and O2. Both theoretical and experimental studies a re reported. The theory is in excellent agreement with experiment. At earlier pump-probe delays, the time evolution of the polarization recu rrence is well described by a rigid rotor model. Higher order spectros copic constants are extracted from longer delay time spectra. The rota tional relaxation constants for ground vibronic state N2 and O2 are al so measured using the real-time technique.