The field of plasmonics offers a route to control light fields with metallic nanostructures through the excitation of surface plasmon polaritons. These surface waves, bound to a metal dielectric interface, can tightly confine electromagnetic energy. Active control over surface plasmon polaritons has potential for applications in sensing, photovoltaics, quantum communication, nanocircuitry, metamaterials and super-resolution microscopy. 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.
Nature Photon.

Gjonaj, B., Aulbach, J., Johnson, P. M., Mosk, A., Kuipers, K., & Lagendijk, A. (2011). Active spatial control of plasmonic fields. Nat. Photon., 5, 360–363. doi:10.1038/nphoton.2011.57