Ionization of oriented carbonyl sulfide molecules by intense circularly polarized laser pulses

Abstract

We present combined experimental and theoretical results on strong-field ionization of oriented carbonyl sulfide molecules by circularly polarized laser pulses. The obtained molecular frame photoelectron angular distributions show pronounced asymmetries perpendicular to the direction of the molecular electric dipole moment. These findings are explained by a tunneling model invoking the laser-induced Stark shifts associated with the dipoles and polarizabilities of the molecule and its unrelaxed cation. The focus of the present article is to understand the strong-field ionization of one-dimensionally-oriented polar molecules, in particular asymmetries in the emission direction of the photoelectrons. In the following article [Phys. Rev. A 83, 023406 (2011)] the focus is to understand strong-field ionization from three-dimensionally-oriented asymmetric top molecules, in particular the suppression of electron emission in nodal planes of molecular orbitals.

Time-dependent generalized-active-space configuration-interaction approach to photoionization dynamics of atoms and molecules

“…There is currently a strong interest in the elucidation of this question. For example in the OCS molecule, experiments with circularly polarized light and theory show that ionization occurs most readily from the O-end, i.e., when the field points towards the Send [85][86][87]. For linearly polarized light, on the other hand, one experiment reports most ionization from the Send [88], while another most perpendicular to the molecular axis [89].…”

Ionization of one- and three-dimensionally-oriented asymmetric-top molecules by intense circularly polarized femtosecond laser pulses

“…In Ref. [23], we modified the tunneling model to include the Stark shifts of the molecule and its cation at the instantaneous value of the external field. We briefly summarize the model here for completeness.…”

Role of Multi-Electron Effects in the Asymmetry of Strong-Field Ionization and Fragmentation of Polar Molecules: The Methyl Halide Series

“…This molecule has been examined by several research groups using different methods. [26][27][28][29][30][31] According to the most elementary theories, the SFI rate is expected to be largest when the electron is removed via the S atom where the density of the HOMO is maximal. However, Holmegaard et al 26 showed experimentally that for circularly polarized laser pulses with a peak intensity of ≈ 2.4 × 10 14 W/cm 2 the ionization of OCS is enhanced when the field points from the O to the S atom.…”