Molecular frame photoemission in multiphoton ionization of small molecules induced by linearly and circularly polarized light

2009 IOP Publishing Ltd. We report results for one-color multiphoton dissociative ionization (MPDI) of NO2 induced by linearly (P) and circularly (k, ) polarized femtosecond (fs) pulses centered at 400 nm. The experiments were performed by combining the use of 1 kHz femtosecond laser sources (SLIC, Saclay) and the electron-ion vector correlation method. The recoil frame photoelectron angular distributions (RFPADs), derived from the analysis of the (Ve, VNO+) velocity vector correlation, are analyzed using a new formalism. It generalizes the expression of the MFPADs for one-photon photoionization of linear molecules, and models the reaction as n-1 bound-to-bound transitions and ionization induced by the nth photon. The polar and azimuthal angle dependences of the RFPAD are characterized. We illustrate the discussion by the RFPADs measured for a MPDI process induced by five-photon absorption.

Molecular frame photoemission in multiphoton ionization of small molecules induced by linearly and circularly polarized light Conference Paper