CHEMICAL GENERATION OF OPTICAL GAIN AT 471 NM

Stimulated emission on the P(43) and R(70) transitions of the BiF (A-X, nu' = 1 to nu'' = 4) band was demonstrated, using the reaction of premixed FN3 and Bi(CH3)3. The transient chemistry was thermally initiated by a pulsed CO2 laser, using SF6 as a sensitizer, while amplification was detected using an etalon-tuned pulsed dye laser probe and a sensitive cavity ringdown technique. The magnitude of the peak gain, estimated at 3.6 x 10(-4)/cm, was consistent with a negligible concentration of the terminal BiF(X, nu'' = 4) state, based on the calculated optical cross section and the peak concentration of the BiF (A, nu' = 1) state, as measured by absolute photometry.