Physics Colloquium: How to Tame a Terahertz Photon with a Metasurface

Zoom: https://tau-ac-il.zoom.us/j/86384445155?pwd=FHiR4BCxtWBaV04yzCXfZbAUNNlhyO.1

Abstract: 

In the last couple of decades, there have been dramatic advances in the generation, manipulation, and detection capabilities of THz waves (0.1-10 THz). These advances forecast a variety of emerging applications in science and technology. However, despite the immense recent progress, there is still a substantial lack of simple methods to generate fully controlled THz waveforms. 

In the presentation, I will introduce the ability of nano-engineered plasmonic metasurfaces to generate broadband and highly controlled THz waves. I will explain the underlying physical mechanisms that make the THz emission from ultrathin metasurfaces comparable in strength to that emitted from orders of magnitude thicker nonlinear crystals, under similar excitation conditions. Furthermore, I will demonstrate how simple electromagnetic considerations can be harnessed to amplify the THz radiation from metasurfaces by more than an order of magnitude. Next we will shift to see how to utilize the well-known Pancharatnam-Berry phase to obtain unprecedented spatio-temporal control over the amplitude, phase, and polarization of the emitted THz waves, opening the door for realization of holographic THz emitters.  If time permits we will also discuss the role of optical phonons in thin-films of nonlinear crystals as promising means for future on-chip enhanced THz emitters and detectors. 
 

Event Organizer: Dr. Hadas Soifer