Coherent population transfer in multilevel systems with magnetic sublevels .3. Experimental results

The technique of stimulated Raman adiabatic passage (STIRAP) has become an established procedure for producing complete population inversion in atoms or molecules via application of Stokes and pump pulses in a counterintuitive sequence. Previously we reported on numerical and analytical investigations showing some of the additional and important phenomena that arise when some of the levels involved have nonzero angular momentum, the field polarization directions have no simplifying symmetries, and Zeeman splitting lifts the magnetic sublevel degeneracy. Here we verify our theoretical findings using the metastable neon system: P-3(0) double left right arrow(3)P(1) double left right arrow(3)P(2) with the corresponding angular momentum sequence J=0 double left right arrow J=1 double left right arrow J=2. In particular, we demonstrate that it is possible to transfer ail population from the single initial state to any single selectable final magnetic sublevel M. Selectivity can be achieved either by choosing special laser polarization angles or, for fixed polarizations, by tuning the two lasers into two-photon resonance between the initial and desired final state. The complete control of magnetic sublevel population enabled by this procedure extends the customary experimental methods for producing oriented or aligned beams of atoms. In addition, we demonstrate very clearly the previous prediction that population transfer may fail for certain sets of parameters (detunings, Rabi frequencies, and polarization angles).