Dark-mode lightning-rod effect in meta-structures

A dark-mode lightning-rod effect has been studied using the meta-structures. In the meta-structure, the metal wires with the tapered terminals are employed as the dark resonators. Due to near-field coupling between the bright and dark modes, electromagnetically induced transparency (EIT) and energy transfer between the incident field and the dark mode can be achieved. The simultaneous dark-mode excitation and surface-charge accumulation near the sharp tip give rise to both spatial confinement and spectral concentration of electromagnetic energy. The enhanced far-field transmission and strong near-field enhancement near the narrow EIT peak may provide a strategy for enhancing the light–matter interactions.