Tunable plasmon resonance in the nanobars and split ring resonator(SRR) composite structure

• The transmission spectra are highly tunable as the geometric parameters modifying.
• When the gap distance between the two bars is small, a new dip and peak will exist.
• When introducing asymmetry to the SRR, a new sharp peak accompany with a dip exists.
• We also find that the proposed structures with sensing sensitivity of ~467 nm/RIU.

We have proposed a multi-band metamaterials composed of bars and planer SRR. There are three sharp peaks in the transmission spectra in the visible and near-infrared region, we find that the transmission spectra are highly tunable as the coupling and geometric parameters modifying, especially the third peak in the near-infrared region. When the gap distance between the two nanobar g1<14 nm, the original first peak will split, a new dip and peak will exist, which is results from the high-order plasmon resonance. When introducing asymmetry to the planer SRR, a new sharp peak accompany with a new sharp dip exists in the original second peak, which is originated from the strong electric field resonance. We also find that the proposed structures with sensing sensitivity of ~467 nm/RIU, which can be used for plasmonic sensor.