Selective excitation of molecular eigenstates using state-dependent optical field design

A new feedback algorithm to design laser fields for state-selective excitation of molecular systems is proposed. The population amplitudes and relative phases of the eigenstates are used to generate a field which drives the population flow in the desired direction. Results are presented for both vibrational excitation of hydrogen fluoride and selective excitation of one of two degenerate electronic states in a model four level system.