Asymmetric coupling between subradiant and superradiant plasmonic resonances and its enhanced sensing performance.
We present symmetric and asymmetric couplings within a pair of split-ring resonators (SRRs). The former shows a single transmittance dip, following the equivalent circuit model; yet, the latter introduces an additional transmittance peak, stemming from an asymmetrically coupled resonance (ACR) between the subradiant and superradiant modes. The mechanism of such induced transparency is elucidated well by the suppression of induced currents within the SRR element with a lower quality factor. Finally, the excitation of ACR is further associated with remarkable confinement of electromagnetic field, providing a compelling sensing performance based on its excellent sensitivity and figure of merit.
Chen
Chia-Yun
CY
Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan, ROC.
Un
Ieng-Wai
IW
Tai
Nyan-Hwa
NH
Yen
Ta-Jen
TJ
D015374:Biosensing Techniques; D004867:Equipment Design; D008422:Materials Testing; D055096:Optical Devices; D055095:Optics and Photonics; D011827:Radiation; D012031:Refractometry / Q000295:instrumentation* / Q000379:methods; D020349:Surface Plasmon Resonance / Q000295:instrumentation* / Q000379:methods