Selective vibrational excitations in the OX (X = F, Cl, Br, I) molecules

Using ab initio calculated potential energy and electric dipole moment func tions for the X(2)Pi states of OF, OCl, OBr and OI, two models have been te sted to selectively populate their vibrational modes by ultrashort coherent light pulses. For a given form of the pulses either a perturbative approac h using discrete vibrational eigenstates and electric dipole transition mom ent matrix elements or a wavepacket propagation technique were used. The op timisation of the pulse parameters and the mechanisms of the multiphoton pr ocesses are discussed. For the target level v=10 populations of more than 6 0% have been achieved in all four molecules. For OCl it was possible to pop ulate selectively all target levels between v=2 and v=15 using chirped puls es.