Rotational interference in vibrational ladder climbing in NO by chirped infrared laser pulses

Results from experiments and model calculations on rotational interference in vibrational ladder climbing in the X²P_1/2 state of NO are presented. In the low-fluence limit, the population in excited vibrational states shows an oscillatory behaviour as a function of the chirp of the IR laser pulse. The interference is due to the accumulated phase difference of pathways involving different intermediate rotational states. The theoretical results match the experiments on an absolute scale.