The science of wave-matter interactions has undergone a significant transformation over the past decade with the introduction of metasurfaces, which are two-dimensional counterparts of volumetric metamaterials. These artificially engineered surfaces have opened up previously unimagined avenues for achieving unprecedented levels of wave-matter interactions, ranging from acoustics to optics, while overcoming typical constraints of bulk metamaterials. Within the realm of surface electromagnetics, the artificial engineered surfaces provide extraordinary EM properties that go beyond the limits of existing materials, and they are widely used to manipulate the amplitude, phase, polarization, wave-vector, and other properties of EM waves. These artificial platforms have exerted a substantial influence across diverse domains, including but not limited to communication, bio-medical, computing, and quantum. The temporal modulation of material characteristics, either independently or in conjunction with spatial modulations, has further unlock the potential of metasurfaces for extreme wave manipulation, leading to time refraction, magnetless non-reciprocity, wave synthesis, signal amplification, frequency conversion, among many others. Additionally, the current vision of the forthcoming (6G and beyond) wireless communication systems relies on the reprogrammable wave functionalities and self-adaptability. Integrated communication and sensing are among the potential technologies that could be used in 6G systems.
In a series of ongoing investigations, I am exploring the coarsely discretized metasurface architecture/metagratings. In the realm of coarse discretization, the periodicity selects a discrete set of Floquet channels referred to as Floquet-Bloch modes – a series of propagating and evanescent plane waves excited by periodic structure. The metasurface is designed with a specific periodicity in order to redirect an incoming wave towards one of the higher order propagating FB modes, rather than imposing an additional transverse momentum.
Additionally, I am working on some new and exciting directions in spatiotemporal metasurfaces, which serve as the fundamental entity for designing active reconfigurable intelligent surfaces (RIS) or smart reconfigurable metasurfaces envisioned for next-generation communication systems.