Multiple optical pulse propagation and population transfer in molecular vapor

We discuss population transfer in K-2 vapor during the production of optica lly pumped laser (OPL) emission. The OPL emission is produced with a pump l aser tuned to a selected K-2(B(1)Pi(u) - X(1)Sigma(g)(+)) transition and is observed to occur on one or more transitions back to the ground state. Amp lification of a probe laser emission introduced in the counterintuitive seq uence and tuned to one of the OPL emission transitions is observed. The exp erimental results are compared to computer simulations. The simulations sho w that 80% of the system population ends up in the terminal level of the OP L emission in K-2 vapor. (C) 1999 Elsevier Science B.V. All rights reserved .