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The influence of aggregates and solvent aromaticity on the photophysics and fluorescence dynamics of two conjugated polymers is studied. It is concluded that the polymer conformation adopted in the aromatic solvent leads to a higher fluorescence quantum yield and a longer fluorescence lifetime.

The photobleaching properties of a group of pyrylium salts under ultrashort-pulsed illumination are experimentally investigated, thus showing that two different photobleaching mechanisms are simultaneously present in all the pyrylium salts. However, during photobleaching of pyrylium salts, some parameters of each mechanism were influenced by the substituent change and showed the presence of multiphoton interactions depending on the specific substituent.

A study was conducted to examine the two photon absorption (TPA) and photophysical properties of three new symmetrical chromophores with electron accepting phthalimide edge substituents. The experimental results for TPA photobleaching of solid poly(methylmethacrylate) films doped with the fluorene molecule revealed that the material could be used as an efficient TPA optical data storage medium.

The steady state and femtosecond time resolved upconversion spectroscopy are used to study the cationic water-soluble poly(fluorenevinylene-co-phenylenevinylene) in aqueous and EtOH solutions. The contribution of the energy transfer process as well as of the isolated chains and the aggregates on the overall fluorescence decay of the polymer and the dependence of the energy transfer rate and efficiency on polymer concentration are determined.

The excited-state dynamics of two oligothiophenes, 5,5'-dicarboxyhaldehyde 2,2',5',2''-terthiophene and 5-carboxyhaldehyde 2,2',5',2''-terthiophene, are studied by time-resolved fluorescence spectroscopy, in the femtosecond regime. The nonsymmetric oligothiophene molecule exhibits shorter excited-state isotropic decay time than the symmetric one.