Polyelectrolyte multilayers for plasmonics and picosecond ultrasonics This thesis investigates the application of polyelectrolyte multilayers in plasmonics and picosecond acoustics. The observed samples were fabricated by the spin assisted layer by layer deposition technique that allowed a precise tuning of layer thickness in the range of few nanometers. The first field of interest deals with the interaction of light induced localized surface plasmons (LSP) of rod shaped gold nanoparticles with the particles environment. The environment consists of an air phase and a phase of polyelectrolytes whose ratio affects the spectral position of the LSP resonance. Measured UV VIS spectra showed the shift of the LSP absorption peak as a function of the cover layer thickness of the particles. The data are modeled using an average dielectric function instead of the dielectric functions of air and polyelectrolytes. In addition using a measured dielectric function of the gold nanoparticles the position of the LSP absorption peak could be simulated with good agreement to the data. The analytic model hel…