Optical characterization of alkyl-thiophenic monomers functionalized with second-order nonlinear chromophores

A series of thiophenic monomers functionalized with different chromophoric groups have been optically characterized in view of preparation of polymeric films for second-order nonlinear optics and electrooptics. In order to investigate the optical behaviour inside a solid host matrix, the molecules have been physically dispersed in poly(methylmethacrylate) (PMMA) films and poled through high-temperature corona-poling for characterization through in situ second harmonic generation and ex situ angle-resolved spectroscopy. The values of dipole moment μ and optical hyperpolarizability β have been estimated inside the host matrix and related to the molecular structure. For one of the chromophores the long-term reorientation dynamics has been monitored in order to investigate the stability and the interaction with the polymeric environment.