COHERENT DYNAMICS OF N-LEVEL ATOMS AND MOLECULES .3. ANALYTICALLY SOLUBLE PERIODIC CASE

By employing an analogy with a spin-J system in a constant magnetic field the authors obtain a simple soluble model for stepwise laser excitation of an N-level system (N=2J+1), including analytic treatment of Doppler detuning and of ionization loss. The solutions are periodic and hence permit complete population inversion. A simple graphical realization of the population dynamics, a generalization of the Feynman, Vernon, and Hellwarth vector model of the two-level Bloch equation, is then described. © 1979 The American Physical Society.