Electrically Driven Unidirectional Optical Nanoantennas

Abstract

Directional antennas revolutionized modern day telecommunication by enabling precise beaming of radio and microwave signals with minimal loss of energy. Similarly, directional optical nanoantennas are expected to pave the way toward on-chip wireless communication and information processing. Currently, on-chip integration of such antennas is hampered by their multielement design or the requirement of complicated excitation schemes. Here, we experimentally demonstrate electrical driving of in-plane tunneling nanoantennas to achieve broadband unidirectional emission of light. Far-field interference, as a result of the spectral overlap between the dipolar emission of the tunnel junction and the fundamental quadrupole-like resonance of the nanoantenna, gives rise to a directional radiation pattern. By tuning this overlap using the applied voltage, we record directivities as high as 5 dB. In addition to electrical tunability, we also demonstrate passive tunability of the directivity using the antenna geometry. These fully configurable electrically driven nanoantennas provide a simple way to direct optical energy on-chip using an extremely small device footprint.

Electromigration-induced resistance switching in indented Al microstrips

“…With the years, researchers have first learnt to mitigate the wearout problem, and later on to master it. As of today, some degree of control of this inherently stochastic phenomenon has been achieved, permitting to create nanogaps for addressing nanoclusters or single molecules [2][3][4], locally modify the geometry or the material properties to fabricate point contacts [5][6][7], superconducting weak links [8][9][10], nanoheaters [11], plasmonic nanoantennas [12], etc. In addition, recent works also showed that the change of electrical resistance in random networks of conducting nanowires under electric bias can induce percolation in these materials, making them interesting transparent conducting materials suitable in a wide range of applications, as window electrodes, transparent heaters, antennas, etc [13,14].…”

Design of plasmonic directional antennas via evolutionary optimization

“…Another optical functionality that is in the focus of the plasmonics community is the directional routing of light. Not only individual nanostructures were demonstrated for directional scattering of far-field light [11][12][13], color-routing [14], quantum emitter radiation steering [9,[15][16][17][18][19], electro-luminescence [20,21] or directional non-linear emission [22]. Also metasurfaces for directional scattering and color-routing have been proposed [23,24].…”

Optical antennas driven by quantum tunneling: a key issues review

“…Directional emission of an optical antenna driven by IET was achieved by Gurunarayanan et al with the design illustrated in Fig. 7(a) [134] . It consists of two electrically connected rod antennas that are aligned edge to edge at an angle of 90 • .…”