Dissociative ionization of D-2 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 pola rized 400- and 800-nm laser pulses. At 800 nm, the D+ ions resulting from t he dissociation of the molecule are observed to be parallel to the polariza tion of the laser field, At the shorter wavelength (400 nm), we observe tha t a considerable number of D+ ions are ejected perpendicular to the polariz ation of the laser field. This observation is interpreted in terms of the r adiative coupling between the ground 1 s sigma(g), and the high-lying 3d si gma(g) and 3p pi(u) electronic states of D-2(+). This interpretation was ve rified by comparing the experimentally measured and theoretically predicted kinetic energy of the D+ ions. Our results indicate that the radiative cou pling between the ground and highly excited electronic states must be consi dered when intense laser fields with high frequencies are used.