Shaping coherent excitation of atoms and molecules by a train of ultrashort laser pulses

摘要

We propose a mechanism to produce a superposition of atomic and molecularstates by a train of ultrashort laser pulses combined with weak control fields.By adjusting the repetition rate of the pump pulses and the intensity of thecoupling laser, one can suppress a transition while simultaneously enhancingthe desired transitions. As an example, various superpositions of vibrationalstates of the $K_2$ molecule are shown.