Complete trapping of light with asymmetric plasmonic resonator arrays

摘要： Trapping/absorption of light in metallic micro/nano-structures on a dielectric-interspaced metal layer were widely studied, but discrepancies in results suggests uncertainty in its perfectness. Here we propose a modified structure with asymmetric resonance elements in each unit cell for complete trapping/absorption of light. In principle, the coupled asymmetric resonators oscillate anti-symmetrically under a critical matching condition, such that leaky radiations from the resonance elements are fully canceled in the far field, which results in guaranteed complete trapping/absorption of light in the near field. The structure may be applied in optoelectronic and bio-chemical sensing devices for strong light–matter interactions.