A plasmonic switch based on electrically controlled cavity resonances

The ability to control and manipulate electromagnetic energy at the nanoscale, both dynamically and in real-time through low-energy external control signals is a missing link in our aim to develop a fully integrated sub-wavelength optical platform. To date, plasmonic systems demonstrating active functionalities, incorporating thermo- and electro-optic media, quantum dots, and photochromic molecules, are achieving incremental progress in switching and modulation applications. However, long switching times (>nanosecond) or the need for relatively strong control energy (~μJ/cm ) to observe sensible signal modulation (35% to 80%) limit the practical use of such structures as signal processing or other active opto-electronic nanodevices. In order for active plasmonics to offer a viable technological platform, both the magnitude and the speed of the employed nonlinearity, as well as the spectral/spatial tunability of the effect must be improved.In this context, we numerically demonstrate an active electro-optical field-effect plasmonic switch based on a resonant cavity structure incorporating indium tin oxide (ITO).