All optical triple resonance

It ought to be pointed out that the methods of transfer of population and also of polarization between the states are being developed further. One might mention, in particular, the cw all-optical triple resonance (AOTR) method evolved by Stwalley s group [282] and tried out on Na2-The method consists of the use of three tunable single-frequency continuous wave lasers allowing flexible movement of both population and polarization from the thermally populated level to any other level of the ground state. 

Tsai, C.C., Bahns, J.T., and Stwahey, W.C., Observation of Na2 Rydberg states and autoionization resonances by high resolution all-optical triple resonance spectroscopy, Chem. Phys. Lett., 236, 553, 1995. 

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