2/6/16

You are invited to attend a lecture

By:

Mr. Greg Kaplan

M.Sc. student of

Professor Jacob Scheuer of Electrical Engineering, Physical Electronics Department Tel Aviv University

Dynamically Controlled Plasmonic Nano-Antennas

Plasmonic nano-antennas at optical frequencies have been the focus of numerous studies during the last decade, resulting in applications ranging from spectroscopy and near-field microscopy to non-linear optics, holography, sensing and many others. Dynamically controlling the resonance frequency or the phase response of a nanoantenna is highly desirable, both for post-fabrication tuning and to enable novel applications such as an optical phased array. The latter concept facilitates beam steering and shaping without mechanical motion, and is therefore much sought after, with possible applications including laser steering for free-space optical communication, LIDARs, dynamic holographic displays and chip-scale photonic devices.

In the first part of the talk a reflective nano-antenna array utilizing vanadium dioxide (VO₂) as a means of continuous electrical steering of an incident IR beam will be proposed and analyzed. VO₂ is a phase-change material, which exhibits a phase transition around 67°C, accompanied by a large shift in its refractive index. The proposed device is a 1D finite array of slots in a gold film deposited over a layer of VO₂, supported by an alumina substrate. For the presented configuration we find that the phase response can be tuned over a range of 2.2 rad, yielding a steering angle of up to from the normal, with a temperature gradient of less than 10°C across the array.