Efficiency and robustness of adiabatic passage by light-induced potentials

We demonstrate numerically the conditions where a wave packet adiabatic passage method yields optimal results for selective excitation of a vibrational level on excited electronic states in molecules. In a recent contribution Garraway and Suominen [Phys. Rev. Lett. 80, 932 (1998)] introduced the method of adiabatic passage by light-induced potentials (APLIP). Here we test and analyze the robustness of the APLIP process under realistic conditions for exciting the ground vibrational state of the Na₂ molecule to the ground vibrational level of the excited ¹Σg(4s) state. The spatial and temporal adiabaticity of the process assures the conservation of the vibrational quantum number during the passage and leads to the remarkable robustness of the method, which at some extent prevents the usual rotating-wave approximation to be employed.