Observation of Fluorescence from High-Lying States of Potassium in a Sodium-Potassium Mixture Upon Resonant Laser Excitation

Fluorescence from three of the highly excited states of K (6S, 5P, and 4D) has been observed in a mixed vapour of sodium and potassium upon irradiation of two cw dye lasers tuned to the D resonance lines of sodium and potassium. Processes that may populate these levels via K*(4P) + Na*(3P) collisions are discussed.