D₂²⁺ dication as a probe of spatial alignment of D₂ molecules in intense laser light

Abstract

The dissociative double ionization of D₂ has been studied in a 532 nm, linearly polarized laser field with intensities in the range 10¹³-10¹⁴ W cm^-2. The laser-field-induced dipole moment gives rise to a torque on D₂ molecules that tends to dynamically align the D-D axis parallel to the laser polarization vector. From measurements of the dependence on polarization angle of the kinetic energy of the D⁺ + D⁺ fragment pairs a simple method, which may be of wide applicability, is developed that yields semiquantitative information on the fraction of molecules that are spatially aligned by the linearly polarized laser field.