Fine-Structure Transitions Occurring in Collisional Redistribution of Light

Experimental results on fine-structure transitions occurring in collisional redistribution of far--off-resonant radiation are presented. Measurements on Na-Ar atomic collisions illustrate that electronically nonadiabatic transitions occurring in the final state, following absorption, are important for describing the redistribution process. The results also provide details of the fine-structure transition process that are not obtainable from the usual resonant scattering experiments.