Third order optical nonlinearity in basket handle porphyrins-picosecond four-wave mixing and excited state dynamics

Abstract

We report degenerate four-wave mixing studies of basket handle porphyrins using picosecond pulses at 532 nm. A qualitative correlation is made between the third order susceptibility and deformation of the molecule. It is postulated that the deformation from a planar structure reduces the susceptibility because it hinders the delocalisation of the p electrons in the molecule. The decay profiles of the DFWM signals have been measured and excited state dynamics in these molecules are inferred from these profiles.