Electrical and picosecond optical control of plasmonic nanoantenna hybrid devices

Miniaturization of optical components for on-chip integration of electronic and photonic functionalities is one of the new frontiers with the promise of enabling a next generation of integrated optoelectronic circuits. A particularly fascinating prospect is the achievement of an optical analogue of the electronic transistor, which forms the building block of our computers. Our approach involves a nanoscale version of a radiowave antenna, the plasmonic nanoantenna. Plasmonic antennas are designed to overcome the diffraction limit of light and to focus light into a nanometer-sized antenna 'feed' gap.

In our first studies supported by EPSRC we have proposed a variety of devices exploiting hybrid interactions of a nanoantenna with an active substrate. Here, we aim to launch a full-scale investigation of such hybrid antenna devices including various geometries and metal oxide substrates, where the plasmonic antenna will be exploited as a nanoscale sensitizer for the active substrate. Integration of a nanoantenna switches with a nanoelectronic transistor will yield a new class of optoelectronic devices: the nanoantenna MOSFET.

The proposed optically and electrically controlled nanoantenna devices are of enormous interest as a bridge for on-chip control of electrical and optical information. In addition, ultrafast active control of local fields and antenna radiation patterns will enable new applications in nonlinear optics, Raman sensors, and optical quantum information technology.

Some very fundamental barriers loom ahead which will severely restrict what can be squeezed out of silicon technology. We are already approaching the limits of miniaturization where the atomistic nature of matter introduces uncontrollable variability in device behaviour.

Optical devices are widely used in the telecommunication area, and have been applied as board level global interconnects. Introducing optical interconnects into the Si architecture itself requires compatibility with CMOS technology. The development of a fast and cost efficient electro-optical modulator is one of the most challenging tasks on the path towards realizing on-chip optical interconnects.

The proposed nano-switch antennas can act as a miniature nanometer-sized light (or more precise plasmon) source and electro-optical modulator at the same time. There is currently an enormous scientific interest worldwide in plasmon-based nanotechnology. The concepts of antenna switches will be of considerable interest to academic researchers including plasmonics and nanophotonics scientists, quantum information scientists, silicon photonics experts, chemical scientists, and electronics experts. In addition to IP arising from this work (which we will aim to protect through patent applications and exploit with advice and expertise from staff in the Research & Innovation Services in the University of Southampton), the project has the potential to deliver high impact publications - internationally leading journals such as Science, Nature Materials, Nature Photonics, Nano Letters, and Physical Review Letters will be targeted to ensure wide exposure among the academic community, and the results will be disseminated through presentations by the investigators and researchers at appropriate international and national conferences (e.g. SPIE Meetings, SPP, CMMP, NanoMeta). These meetings will ensure that the results are disseminated effectively among materials scientists, optics and electronics scientists as well as to industrialists attending.