Plasmon-enhanced diffraction in nanoparticle gratings fabricated by in situ photo-reduction of gold chloride doped polymer thin films by laser interference patterning
We propose a new method for light-induced in situ synthesis of gold nanoparticle gratings in polymer thin films. The polymer films are doped with gold precursors and then irradiated with an interference pattern leading to the spatially controlled photo-reduction of metallic ions. An annealing procedure is then used to induce nanoparticle growth while maintaining the spatial organization within the film. The originality of the method resides in the fact that we use continuous low-power laser excitation in the visible range, which opens the way to large-area manufacturing processes. In terms of optical properties, such fabricated gold nanoparticle gratings exhibit both plasmonic and diffractive properties with plasmon enhanced diffraction efficiency.