Hole-burning experiments, ground state

R. de Vivie-Riedle and J. Manz Prof. Neumark s question about detecting the hole burning in the nuclear wavepacket of the electronic ground state is very stimulating. In this context, we have developed a scheme for detecting the hole in the wavepacket by a femtosecond chemistry laser experiment that involves two laser pulses Our explanation will be for the specific system K2, but more general applications for other systems are obvious ... 

We have adopted the excitonic band model not only because it describes conventional absorption spectroscopy (linear spectroscopy), but because it enables an extremely convenient description of nonlinear experiments, such as pump-probe, dynamical hole burning, or photon echoes. In these third-order experiments one has to consider not only transitions from the ground state to the one-excitonic states but also transitions from the one-excitonic to the two-excitonic states (see Fig. 13). These additional transitions reveal the required information to deduce, at least in principle, the complete coupling scheme. 

In contrast to the previous experiments with dilute rare-earth ions, quadrupole splittings in the ground ( F ) and excited ( Z>o) states of Eu " in the stoichiometric rare-earth compound EuPsOu were also determined by laser hole burning and optically detected... 

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