title: Shaping the nonlinear near field.
abstract: Light scattering at plasmonic nanoparticles and their assemblies has led to a wealth of applications in metamaterials and nano-optics. Although shaping of fields around nanostructures is widely studied, the influence of the field inside the nanostructures is often overlooked. The linear field distribution inside the structure taken to the third power causes third-harmonic generation, a nonlinear optical response of matter. Here we demonstrate by a far field Fourier imaging method how this simple fact can be used to shape complex fields around a single particle alone. We employ this scheme to switch the third-harmonic emission from a single point source to two spatially separated but coherent sources, as in Young's double-slit assembly. We envision applications as diverse as coherently feeding antenna arrays and optical spectroscopy of spatially extended electronic states.
authors.affiliation: Experimental Physics III, University of Bayreuth, Universitätsstrasse 30, D-95440 Bayreuth, Germany.|Max Planck Institute for Solid State Research, Heisenbergstrasse 1, D-70569 Stuttgart, Germany.
authors.forename: Daniela
authors.initials: D
authors.lastname: Wolf
authors.affiliation: Experimental Physics III, University of Bayreuth, Universitätsstrasse 30, D-95440 Bayreuth, Germany.
authors.forename: Thorsten
authors.initials: T
authors.lastname: Schumacher
authors.affiliation: Experimental Physics III, University of Bayreuth, Universitätsstrasse 30, D-95440 Bayreuth, Germany.
authors.forename: Markus
authors.initials: M
authors.lastname: Lippitz