Distortion of molecular electron density distributions by an intense laser field: dissociative ionization of CCl₄

Abstract

The interaction of a tetrahedral molecule (carbon tetrachloride) with intense, 532 nm, 35 ps, 10^L3 W cm^-2 linearly polarized, laser fields is explored theoretically and experimentally. Distortions caused by the laser field in the molecular electron density distributions are computed in an approximate fashion using quantum-chemical techniques. A comparative experimental study is performed of the dissociative ionization of CCl₄ in such an intense laser field and also by electron impact. Significant differences are observed and attempts are made to explore the possibility that these can be explained using field-distorted electron density distributions. Angular distributions of the Cl⁺ fragment ion have also been measured and show a pronounced anisotropy with the ion signal being detected mainly along the direction of the laser's polarization axis.