Executive Summary : | Metasurfaces (Mss) are two-dimensional metamaterials with exotic optical properties, making them suitable for terahertz (THz) components. The THz part of the electromagnetic spectrum spans from 0.1 THz to 10 THz and is potentially available for communication, security, non-destructive evaluation, imaging, and sensing applications. However, the optics required for THz applications are limited by the non-availability of natural materials. Researchers have been exploring the physical properties of metasurfaces for THz wave applications, particularly spatial and time-modulated Mss, which offer dynamic control over the amplitude, phase, and polarization of electromagnetic radiation. Introducing spatial and time modulations in chiral Ms structures can unleash novel non-reciprocal electromagnetic phenomena with customized light-matter interactions and dynamic control over the amplitude, polarization state, and harmonics of THz radiation. The present proposal aims to explore spatial- and time-modulated chiral Ms for the realization of polarization controller, integrated beam-splitter, and wavefront components at THz frequencies. The successful realization of time-modulated THz metasurface will indicate that non-reciprocal elements such as isolators, phase-shifters, and circulators will also be possible for THz regime and be magnet-free. This will pave the way for making a strong footprint in THz optics, allowing for the effective use of deserted wavebands spanning between 0.1 THz to 10 THz. |