Dissociative ionization of D2 in intense laser fields:: D+-ion production perpendicular to the polarization of a 400-nm laser field -: art. no. 042708

Dissociative ionization of the D-2 molecule was studied using linearly polarized 400- and 800-nm laser pulses. At 800 nm, the D+ ions resulting from the dissociation of the molecule are observed to be parallel to the polarization of the laser field, At the shorter wavelength (400 nm), we observe that a considerable number of D+ ions are ejected perpendicular to the polarization of the laser field. This observation is interpreted in terms of the radiative coupling between the ground 1 s sigma(g), and the high-lying 3d sigma(g) and 3p pi(u) electronic states of D-2(+). This interpretation was verified by comparing the experimentally measured and theoretically predicted kinetic energy of the D+ ions. Our results indicate that the radiative coupling between the ground and highly excited electronic states must be considered when intense laser fields with high frequencies are used.