Elahe Nasiri - Department of Electrical Engineering, Faculty of Engineering, Lorestan University
Ali Mir - Department of Electrical and Computer Engineering, Faculty of Engineering, Lorestan University
Ali Farmani - Department of Electrical and Computer Engineering, Faculty of Engineering, Kharazmi University

A tunable nano-modulator based on plasmonic planar split-ring resonators is proposed.The effects of Fano resonances are studied to harness the transmission spectra in nearinfrared region. In the structure, dual hexagonal ring resonators are utilized to realize the Fano resonances with the advantages of high sensitivity, large figure of merit, narrow full wave at half-maximum (FWHM), and extremely large Q-factor. Analytical and numerical results show that, by slight variation of the refractive index and geometrical parameters, the characteristics of the propagation of the bright mode anddark mode resonances can be manipulated. A high sensitivity of ۱۱۶۰ nm/RIU with a FoM as large as ۳۳ is achieved. Besides, the proposed structure shows a relatively narrow FWHM of ۵۰ nm, which introduces a high Q-factor of ۳۱. Such this moderately high Q-factor ensures that the structure exhibits extreme low resonance losses that can be advantageous for high resolution detections with acceptable accuracy. Showing a high sensitivity, large FoM, narrow FWHM, high Q-factor, and compact size, the proposed biosensor can find potential applications in fundamental nanoscience studies.

Nano-modulator, Plasmonics, Nanoresonator, Fano Resonance