Polarizability anisotropies of rare gas van der Waals dimers studied by laser-induced molecular alignment

The molecular alignment technique utilizing the interaction between the intense nonresonant laser field and the induced dipole moment is applied to the homonuclear rare gas dimers Rg2 (Rg=Ar, Kr, and Xe). The degree of alignment is investigated by Coulomb exploding Rg2 and by measuring the angular distributions of the fragment ions. At the same peak intensity of the laser field, the degree of alignment ≪cos2 θ ≫ becomes larger in order of Ar2, Kr2, and Xe2, reflecting the order of magnitudes of their polarizability anisotropy Δα. By taking I2 molecules as a reference, Δα of Ar2, Kr2, and Xe2 are estimated to be 0.5, 0.7, and 1.3 Å3, respectively.