Two-Color Four-Wave Mixing: Sensitivity to State Changing Collisions

Energy tranfer by collisions in the ground state X of NH. The DUMP laser is tuned to the Q3(9) transition in the (0-0) band while the PUMP laser is scanned in the vicinity of the Q3(9) upward transition in the (1-0) band. Transitions due to rotational energy transfer between neighboring levels of the directly excited level are observed.