Evidence for continuous visible chemical lasing from the fast near resonant energy transfer pumping of atomic sodium

Energy transfer from selectively formed metastable states of SiO is used to pump sodium-atom laser amplifiers at lambda approximately=569 nm (4d/sup 2/D-3p/sup 2/P), lambda approximately=616 nm (5s/sup 2/S-3p/sup 2/P), and lambda approximately=819 nm (3d/sup 2/D-3p/sup 2/P). The a/sup 3/ Sigma /sup +/ and b/sup 3/ Pi states of SiO are generated in high yield from the Si+N/sub 2/O to SiO+N/sub 2/ reaction. The energy stored in the triplet states is transferred in a highly efficient collisional process to pump sodium atoms to their lowest excited 3d/sup 2/D, 4d/sup 2/D, and 5s/sup 2/S states. Adopting a sequence in which high concentrations of silicon and sodium atoms are mixed and oxidized, a continuous amplification (gain condition) is monitored which suggests the creation of a population inversion among the receptor sodium-atom energy levels and forms the basis for full cavity oscillation on the Na4d/sup 2/D-3p/sup 2/P transition at 569 nm.<
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