Title: Electrically Reconfigurable Phase-Change Antennas and Metasurfaces
Abstract:
Nanoscale optical switches have been a focus of study, as the type of devices could have a transformative impact on the development of dynamic and programmable metasurfaces, optical neural networks, and quantum information processing. Chalcogenide phase-change materials, out of many approaches, are uniquely suited to enable such modulation, because they offer high-speed electrical switching with notably different optical properties. Their high refractive index has already been harnessed to fashion them into compact optical antennas. However, electrical tuning of phase-change antennas and metamaterials has been a challenge.
In this talk, I will present electrically-switchable phase-change antennas and metasurfaces, that offer strong, reversible, non-volatile, multi-phase switching and spectral tuning of light scattering in the visible and near-infrared spectral ranges. Their successful implementation relies on a careful joint thermal and optical optimization of the structure. I will first introduce a phase-change antenna, that offers strong scattering in the visible and near-infrared spectral ranges and substantial electrical modulation of the scattered light intensity. In the second part, I will show a phase-change metasurface, that can achieve electrical modulation of the reflectance.
