Femtosecond-laser-induced alignment in Coulomb explosion of N2

The dynamic process of laser-induced alignment in Coulomb explosion of N-2 has been studied using linearly and circularly polarized, 800 nm, 40 fs Ti:sapphire laser pulses at intensities of 10(14) to 10(16) W cm(-2). The fragment ions produced were observed for the different polarizations with an equal E-field along the detection axis. The intensity-dependent ratio of fragment ion signals has shown that the 40 fs pulses can never align the molecules during the ultrafast interaction at an intensity less than similar to10(15) W cm(-2), and the dissociative molecular ions start to be aligned at higher intensity. The degree of alignment is increased with an increase in the charge of the dissociative molecular ions.