1. from W. Demtröder “Molecular Physics”

2. IR-UV Double Resonance
X, v=0
el. excited state
X, v=1
fluorescence
Technique:
Fix UV laser, scan IR laser, measure fluorescence signal as function of IR frequency to obtain
vibrational spectrum of ground state
Advantage:
“Action spectroscopy” – probe generation of fluorescence photons, background-free, more sensitive than IR absorption

3. Resonant Two-Photon Ionization (R2PI)
|0>
|k>
ionization
continuum
Technique: Scan laser, measure ion signal as function of laser frequency to obtain spectrum of excited state
Advantages:
Mass spectroscopic detection is very sensitive (much better than UV/vis absorption spectroscopy)
“Action spectroscopy” – probe generation of ion, background-free

6. from W. Demtröder “Molecular Physics”