Near-field coupled high Q tunable electrically induced dipole resonance in terahertz meta-waveguide

<jats:title>Abstract</jats:title> <jats:p> We investigate electrically induced, near-field coupled dipole resonant mode with a high-quality factor ( <jats:italic>Q</jats:italic> ) in a terahertz (THz) meta-waveguide. The waveguide structure is composed of I-shaped aluminum metamaterial constituents, placed periodically on a copper-quartz bilayer substrate in the propagation direction of an incident THz beam. The electric field vector is set along a I-shape design in the transverse direction of the meta-waveguide, leading to the excitation of a strong dipole resonance around the I-shaped meta-atom. The dipole resonance is quite sharp with high <jats:italic>Q</jats:italic> values due to the strong interaction of propagating THz wave with the metamaterial design, unlike traditional terahertz metatareials. The THz transmission response of the waveguide is numerically analyzed to study the dipole resonance, which shows the existence of two resonances due to near-field coupling. Furthermore, the excitation of these dipole resonances and their coupling behavior are confirmed by the electric field distribution of the meta-waveguide. Notably, these dipole resonances can be tuned across a range of frequencies which are integrated with the coupling mechanism, offering a practical route for realizing next-generation photonic devices. We also employ a semi-analytical coupled harmonic oscillator theory to understand the underlying physical mechanisms of the dipole resonators in meta-waveguides and to corroborate our numerically obtained transmission results. The tunability of electrically induced high <jats:italic>Q</jats:italic> -dipole resonance leads to promising applications in highly sensitive sensors, storage devices, electromagnetically induced transparency, and on-chip photonic components. </jats:p>