Active spatial control of plasmonic fields

The field of plasmonics(1) offers a route to control light fields with metallic nanostructures through the excitation of surface plasmon polaritons(2). These surface waves, bound to a metal dielectric interface, can tightly confine electromagnetic energy(3). Active control over surface plasmon polaritons has potential for applications in sensing(4), photovoltaics(5), quantum communication(6,7), nanocircuitry(8,9), metamaterials(10,11) and super-resolution microscopy(12). We achieve here active control of plasmonic fields using a digital spatial light modulator. Optimizing the plasmonic phases through feedback, we focus surface plasmon polaritons at a freely prechosen point on the surface of a nanohole array. Digital addressing and scanning of surface plasmon polaritons without mechanical motion may enable novel interdisciplinary applications of advanced plasmonic devices in cell microscopy, optical data storage and sensing.