Classical and quantum mechanical studies of overtone and multiphoton absorption of HF in an intense laser field

Abstract

Classical trajectories and exact quantum dynamics are used to study overtone and multiphoton absorption of HF in an intense laser field. Transition probabilities and energy absorbed are calculated for nonrotating HF at a fixed frequency (ν̄=3922 cm−1), and the initial vibrational state is varied. Quite good agreement between the classical and quantum results is found in this case. Calculations are also performed about the first overtone frequency for both rotating and nonrotating HF. In this case the quantum and classical comparison is much worse with the absorption maxima of the two results shifted by 200 cm−1 from each other. Poincaré surfaces of section are constructed to help interpret and characterize the classical results for nonrotating HF.