Pumping of atomic alkali lasers by photoexcitation of a resonance line blue satellite and alkali-rare gas excimer dissociation

Photoassociation of alkali-rare gas atomic collision pairs provides an alternative approach to optically pumping atomic alkali lasers. Lasing on the 6 P21/2→6 S21/2 (D1) transition of Cs has been observed when the blue satellite of the 6 P23/2←6 S21/2 (D2) transition, peaking at ∼837 nm for mixtures of Cs vapor, Ar, and ethane, is pumped by a pulsed dye laser. For 50% output coupling, laser threshold with respect to absorbed pump energy is ∼40 μJ at T=435 K and the slope efficiency approaches 10%. The measured spectral breadth for the blue satellite (≳5 nm at 410 K) will accommodate cw pumping of the Cs laser with conventional semiconductor lasers.