Fully differential study on dissociative ionization dynamics of deuteron molecules in strong elliptical laser fields

Abstract

Deuteron momentum distributions from the dissociative ionization of ${\mathrm{D}}_{2}$ in intense elliptically polarized laser fields have been explored in a joint experimental and numerical study. The asymmetrical charge localization in the dissociative ${{\mathrm{D}}_{2}}^{+}$ offers a large torque, and thus an elliptically polarized laser field efficiently rotates the molecular ion during its dissociation, resulting in the emission of deuterons finally deviating from the bond direction at the instant of tunneling ionization of ${\mathrm{D}}_{2}$. The rotating torque of the molecular ions increases with the field ellipticity, leading to an ellipticity-dependent tilt angle for the deuteron momentum distribution. Due to the notable rotation of ${{\mathrm{D}}_{2}}^{+}$ during its dissociation, the photoelectron angular distributions in the laboratory frame and the molecular frame are distinct, which illustrates that the axial recoil approximation is broken for discussing the photoelectron angular distributions of molecules in elliptically polarized laser fields.