Coupling effect combined with incident polarization to modulate double split-ring-resonator in terahertz frequency range

This work examines the coupling effect in concentric double split-ring-resonator devices in terahertz (THz) range when the inner ring changes its relative orientation to the outer ring. Through detailed analysis on the simulation results of surface current and electrical field distributions, we look into the changes of inductance and capacitance in the system caused by structural layouts, and present a set of coherent theory that is solely rooted in the inductance-capacitance circuit analogy to systematically account for the resonance change. Such coupling effect combined with polarization of the incident wave is further explored to demonstrate continuous modulation of THz resonances. A variation range of transmission intensity from 20% to 80% has been successfully achieved. These experimental results demonstrate the promise of realizing future tunable THz filters by means of rotating sub-structures of the device only. (C) 2014 AIP Publishing LLC.