Dynamic Beam Steering By A Reconfigurable Metasurface
You are invited to attend a lecture on Sunday, November 29, 2020 13:00
ynamic Beam Steering by a Reconfigurable Metasurface
By: Bar Zirinski
M.Sc. student under the supervision of Prof. Jacob Scheuer
Abstract
In this thesis we demonstrate dynamic beam steering by mechanically tuning a flexible beam deflector metasurface. For this purpose, we design a plasmonic beam deflector metasurface and fabricate it on a flexible substrate made of PDMS. The deflective metasurface is a two dimensional array of resonant sub-wavelength meta-atoms operating at 1550 nm. We characterize the metasurface optical and mechanical responses under external strain in a uniquely designed set-up. The mechanical tuning is obtained by a stretching device able to strongly clamp and stretch the flexible metasurface, allowing the monitoring and controlling of the applied external strain.
The functionality of a metasurface is determined by its phase profile which is implemented by meta-atoms, where each of them has a specific phase and amplitude response. Stretching a deflector changes the array geometry which in turn changes the aperture phase function. This results in a continuous change of the deflection angle, thus creating a dynamic beam scanner.
The results obtained in this thesis validate the potential of reconfigurable metasurfaces to yield dynamic beam steering- an essential building block for both existing and future optical systems.
Dynamic control over metasurface functionalities via external signals would unlock major opportunities for science and applications. Moreover, integration of flexible metasurfaces and external mechanical actuation is highly attractive and advantageous. The main goal of this study is to make progress towards the integration of reconfigurable metasurfaces with N-MEMS technology in order to create a complete dynamic optical system. Such integration will establish a powerful new technological platform. If employed as an infrastructure, it is very likely to give rise to the development of new applications and devices.
