Berlin 2015 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

O: Fachverband Oberflächenphysik

O 5: Plasmonics: Nanoantennas, Nanoparticles

O 5.2: Vortrag

Montag, 16. März 2015, 10:45–11:00, MA 042

Electrically-driven optical antennas — •René Kullock¹, Johannes Kern^1,2, Jord Prangsma³, and Bert Hecht¹ — ¹Experimental Physics 5, University of Würzburg, Germany — ²Physikalisches Institut, University of Münster, Germany — ³MESA+ Institute for Nanotechnology, University of Twente, Enschede, The Netherlands

Antennas play a key role in today's wireless communication networks as they efficiently link localized electrical signals and electromagnetic waves. Driven by the demand for higher bandwidth, antenna carrier frequencies are ever increasing, however, electrically driven nanoantennas at optical frequencies seemed beyond reach. Although fabrication of optical antennas is already possible, unlike radiowave antennas they are not fed by a generator. Instead they are driven by light directly or via optically active materials in their proximity.

Here, we demonstrate direct electrical driving of an optical nanoantenna featuring an atomic-scale feed gap. Upon applying a voltage, quantum tunneling of electrons across the feed gap creates a broadband quantum shot noise. The optical frequency components of this fluctuating current are efficiently converted into photons by the antenna. We demonstrate that the properties of the emitted photons can be fully controlled by the antenna architecture, and that the antenna improves the quantum efficiency by up to two orders of magnitude with respect to a non-resonant reference system. Our work represents a new paradigm for interfacing electrons and photons at the nanometer scale, e.g. for on-chip wireless data communication.