"IIn this program I will demonstrate control of light at length scales well below the free-space wavelength, leading to entirely new fundamental phenomena and important applications. The research program is built on specially engineered metamaterials composed of metal nanostructures that support surface plasmons that are embedded in a dielectric. The program is composed of three strongly related topics:1) I will experimentally demonstrate an entirely new class of optical metamaterials that posses a refractive index that can be tuned over a very large range: -10 < n < +10. Based on coupled plasmonic waveguides, these materials will, for the first time, show true left-handed behaviour of light (n < 0) in the UV/blue spectral range. I will demonstrate negative refraction of light and use these materials to demonstrate the “perfect lens” which enables sub-wavelength imaging of (biological) nanostructures.2) I will use plasmonic metamaterials to engineer the flow of light in thin-film solar cells. By controlling the scattering and trapping of light using plasmonic nanostructures integrated with semiconductor waveguide slabs I will demonstrate ultra-thin solar cells with efficient collection and conversion of infrared light, aiming at beating the ergodic light trapping limit.3) I will demonstrate strong coupling between light and mechanical motion in the smallest possible volume. Light trapped in plasmonic metamaterials exerts a force that can lead to a shift in the plasmonic resonance frequency which in turn provides feedback on the mechanical motion. We will use this nanoscale coupling mechanism to actively cool and heat mechanical motion in plasmonic nanostructures and use this phenomenon in a new type of plasmon-based quartz oscillator."