Large area plasmonic nanoparticle arrays with well-defined size and shape

We demonstrate an innovative process to fabricate uniformly shaped plasmonic nanoparticles. Laser interference lithography, nano-imprint lithography and a lift-off process are employed for the controlled production of periodically arranged nanoparticles on large areas. Round and elliptic silver particles with diameters of about 200 nm on an area of 5x5cm super(2) are investigated. Measurements of resonant absorption by the metal particles are in agreement with data computer-simulated by rigorous coupled wave analysis. We observe that the plasmonic resonance of elliptic particles depends on the polarization of incident light and that porosity of the metal influences the plasmonic band.