Some photophysical properties of coumarin-1 dye in different concentrations

الملخص EN

The fluorescence lifetime of coumarin-1 d}-e is measured in the solution of methanol at different concentrations utilizing single photon counting technique.

The variation of fluorescence lifetime with concentration is explained in term of self quenching.

Both internal quenching rate parameters Kim and intersystem crossing rate parameters Kgm are calculated at different concentrations to ensure the participation of the quenching produced by the dimer and other complexes formation.

INTRDDUCTI©N The choice ofa particular organic dye for the^ye laser is based on its satisfying the general requirements such as high fluorescence quantum yield, low triplet—triplet absorption.short singlet state lifetime, high photochemical stability and wide spectral range [!].

However, in a number of cases, it is found that the study of other molecular parameter such as stimulated emission cross - section.