Laser-induced Coulomb explosion, geometry modification and reorientation of carbon dioxide

The Coulomb explosion of carbon dioxide in a 55 fs laser pulse of intensity 1.5-3 x 10(16) W cm(-2) has been studied using a variety of techniques bas ed on time-of-flight mass spectroscopy. Covariance mapping has been used to identify Coulomb explosion channels and to measure the associated kinetic energy release. By comparing time-of-flight spectra taken with linearly and circularly polarized light, a clear signature of laser-induced reorientati on is found, which is strongest for the lowest Coulombic channel. Ion-momen tum imaging coupled with Monte Carlo simulation shows that the zero-point b end-angle distribution is better preserved than for longer laser pulses. Ho wever, some residue of the sequential processes dominant in much longer pul ses is found.