| The first section of this thesis concerns the study of interactions between the intense local plasmonic field generated by nanostructure and a well known photosynthetic protein system, bacteriorhodopsin (bR). bR is a membrane protein responsible for proton transport. Among the many intermediates formed upon photoexcitations, two of the most relevant have been studied. The intermediates under studies were 1460 and M412, and their decay dynamics were measured in presence of the plasmonic field generated by the excitation of their surface electrons using visible photons.;Both intermediates decay lifetime was affected when the plasmonic field was turned on, and it was verify that thermal effect were not the source of the change in dynamic.;The second part concerns the investigation of third-order nonlinearity (chi(3)) of a series of extended conjugated squaraine dyes in the telecommunication spectral region. The chi(3) is measured via Degenerate Four Wave Mixing and Z-scan as function of the dyes increasing conjugation length and number of squarylium groups. The dyes produced large real and imaginary values for chi(3) in the 1.3-1.5 mum range, which makes them attractive for optical limiting type of applications. |
