The measurement of gain on the 1.315 mu m transition of atomic iodine in asubsonic flow of chemically generated NCl(a(1)Delta)

Gain is measured on the electronic I(P-2(3/2))-I*(P-2(1/2)) transition of a tomic iodine at 1.315 mu m when hydrazoic acid HN3 is injected into a flow of iodine and chlorine atoms. The inversion was generated in a transverse s ubsonic flow device that produced electronically excited I*(P-2(1/2)) atoms from the efficient energy transfer reaction between NCl(a(1)Delta) metasta ble and ground state I(P-2(3/2)) atoms. The population inversion was direct ly observed using a 1.315 mu m tunable diode laser that scanned the entire line shape of the (3,4) hyperfine transition of iodine. (C) 1999 Elsevier S cience B.V. All rights reserved.