Laser Coulomb explosion imaging for probing ultra-fast molecular dynamics

Abstract

We use laser Coulomb explosion imaging (CEI) to measure structural change during molecular ultra-fast dynamics. We obtain time information with a pump–probe approach using few-cycle laser pulses (<8 fs). The time required for ionization by the intense probe pulse sets our time resolution at ∼4 fs. Using coincidence imaging, we obtain image information by measuring the vector momenta of all atomic ions produced by Coulomb explosion of a single molecule. We demonstrate the capability of laser CEI by following the motion of vibrating D2+ and of dissociating SO22+ and SO23+ molecules with sub-Å spatial resolution. Using correlation maps, we identify molecules by dissociation channel.