Study of Franck CONDON’s Excited states
We are interested in the first events taking place in the DNA helices, between the moment of absorption of a photon and the photochemical reactions. We study Franck-Condon excited states, the redistribution of excitation energy between various excited states, one-photon ionization as well as the properties of the generated radicals.
The specificity of the group is the use of high-performing time-resolved spectroscopy
DNA and its constituents are fragile systems so particular care is taken with regards to excitation energy and sample handling.
Time-resolved fluorescence (fluorescence decays, fluorescence anisotropy decays and time-resolved fluorescence spectra) can be recorded from 100 fs to 100 ns using a combination of two detection techniques; fluorescence upconversion and time-correlated single photon counting.
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An important asset is the use as the same excitation source (a femtosecond titanium:sapphire laser) in both cases.
Nanosecond flash photolysis allows the monitoring of transient states and species from 10 ns to 100 ms. A specific features of our setup is the detection of weak signals(10-4 en absorbance).
