POPULATION TRANSFER BY STIMULATED RAMAN-SCATTERING WITH DELAYED PULSES AND BY THE STIMULATED-EMISSION PUMPING METHOD - A COMPARATIVE-STUDY

The characteristics of the stimulated-emission pumping (SEP) method and the technique of stimulated Raman scattering by delayed pulses (STIRAP) are compared, based on numerical results from density matrix calculations. The latter technique requires the use of nearly transform-limited pulses, whereas the former method is successfully implemented with broadband lasers. Damping coefficients y are introduced to model the consequences of phase fluctuations of the radiation. It is shown that the various techniques can be classified in terms of the delay D of the Stokes laser relative to the pump laser and the damping rate y. The delay D/ATL -1 and y = 0 corresponds to the STIRAP mode of operation, whereas the SEP method requires that, where ATL is the width of the laser pulse. © 1990 Optical Society of America.