Enhancing optical gradient forces with metamaterials

The transfer of linear momentum from electromagnetic waves to matter and the associated optical force allows to dynamically manipulate the geometry of nanophotonic components with optical fields. In recent years, it has been proposed to use these optical gradient forces for all optical actuation of optical systems. This would open up the possibility for optical information processing inside nanoscale devices. Despite several efforts to increase these forces in integrated systems, they remain too small for most practical applications. In this contribution, we demonstrate how the optical gradient forces can be enhanced significantly with the use of metamaterials. By implementing the techniques of transformation optics, we show how a metamaterial slab allows to increase the optical forces over several magnitudes, even when realistic losses are included.