D-2(2+) dication as a probe of spatial alignment of D-2 molecules in intense laser light

The dissociative double ionization of D-2 has been studied in a 532 nm, lin early polarized laser field with intensities in the range 10(13)-10(14) W c m(-2). The laser-field-induced dipole moment gives rise to a torque on D-2 molecules that tends to dynamically align the D-D axis parallel to the lase r 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 semiquantitati ve information on the fraction of molecules that are spatially aligned by t he linearly polarized laser field. (C) 1999 Elsevier Science B.V.