Studies on non-radiative metamaterials for terahertz photonics

We experimentally (both fabricated and characterized) and theoretically (in CST studio suite, MATLAB) investigate several neoteric strategies to alleviate radiation loss in metamaterials in context of THz photonics. To be precisely, by tailoring near-field coupling and resonance hybridization, several non-radiative phenomena such as Fano resonances, Bound states in the continuum (BICs), and electromagnetic anapoles were demonstrated. The key outcomes of the demonstrated research works are as follows: excitation of Fano resonances in metamaterials without having structural asymmetry and its demonstration in highly sensitive THz sensing; conversion of radiative resonances into non-radiative resonances (Fano, BIC, anapole) by tailoring structural asymmetry and lattice coupling; introducing artificial transverse magnetism (induction of circulation conduction current) in non-magnetic straight solid metallic (conducting) wire, viz. ‘magnetic wire’; incorporation of magneto-transport (GMR, spintronics) concept to dynamically enhance performance of THz metamaterials and introduction of the concept ‘THz spintronic metamaterials’. Such studies are focused on effective concentration of electromagnetic energy at micro- or nano-scale level for utilization in several application areas like sensing, spintronics, plasmonics, communication, and photodetection etc.