Photodissociation Action Spectroscopy vs. Fluorescence Excitation Spectroscopy: an Experimental Comparison

摘要

The PD action spectrum of Rh110 is significantly narrower than its fluorescence excitation spectrum. This is because multiple photons must be absorbed to photodissociate Rh110 while its fluorescence arises from the absorption of a single photon. When absorption cross section is low (e.g. at the edges of the spectrum) the probability of absorbing multiple photons decreases faster than the probability of absorbing a single photon, thus resulting in a narrower PD spectrum than the fluorescence excitation spectrum. The maximum of the PD action spectrum lies ～120 cm~(-1) to the red of the fluorescence excitation maximum of Rh110. This is likely due to the comparatively higher internal energy (effective temperature) of the Rh110 ions under photodissociation conditions.