Resonant High-Order Multiphoton Excitation

The asymmetric dissociation channels discussed in the previous section are closely tied to the charge-resonant states first introduced by Muliken in 1939 [35]. These states have no counterpart in atoms and occur whenever there is a difference in charge state in the dissociation limit of a diatomic molecule. They 

Correlation with early N5 -Correlation with late 

Such a system was independently realized a few years later in a completely different field driven quantum flux qubits [38]. Here, a superconducting loop can support a quantum unit of current in either direction around the loop. In an external dc magnetic field, the degeneracy of the two directions is lifted, 

Plasma excitation would occur on a much longer timescale, while fluorescence from prompt excitation of the 2p level in H could be readily quenched through the ionization of the 2p state with the second laser pulse. 

Finally, there is one other experiment that we know of that found a resonant signature in the strong field excitation of a molecule. In this experiment, the symmetric dissociation channel of 0 + was monitored in a high resolution coincidence ion spectrometer [41]. From the KER of the fragments, excitation to the B3iTg state was identified, among other states. However, this particular 

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A technique which combines the high sensitivity of resonant laser ionization methods with the advantages of nonlinear coherent Raman spectroscopy is called IDSRS (ionization detected stimulated Raman spectroscopy). The excitation process, illustrated in Figure 5, can be briefly described as a two-step photoexcitation process followed by ion/electron detection. In the first step two intense narrow-band lasers (ct L, 0) ) are used to vibrationally excite the molecule via the stimulated Raman process. The excited molecules are then selectively ionized in a second step via a two- or multiphoton process. If there are intermediate resonant states involved (as state c in Figure 5), the method is called REMPI (resonance enhanced multi-photon ionization)-detected stimulated Raman spectroscopy. The technique allows an increase in sensitivity of over three orders of magnitude because ions can be detected with much higher sensitivity than photons. 

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