International Journal of Scientific Research and Engineering Development

Plasmonic metamaterials with nanoscale dielectric gaps offer exceptional electromagnetic field confinement and enhancement, making them ideal for nanophotonic applications. This study presents a comprehensive investigation of silver (Ag) nanorod-based split-rod plasmonic metamaterials with zinc oxide (ZnO) dielectric gap layers using finite-difference time-domain (FDTD) simulations. Two distinct configurations are analyzed: Model A with 300 nm Ag nanorods and 80 nm ZnO gap, and Model B with 200 nm Ag nanorods and 30 nm ZnO gap. The simulations examine the electromagnetic field distribution, transmission and reflection characteristics, and polarization-dependent optical response across the visible to near-infrared spectrum (400–900 nm). Results demonstrate that the ZnO dielectric gap plays a critical role in field localization, supporting multiple resonant modes including guided modes, gap-localized modes, and surface plasmon polariton modes. Model B exhibits stronger field confinement due to the reduced gap thickness, achieving significant field enhancement at the gap region. Polarization angle variation (0° to 70°) enables active control of resonance wavelength and intensity. The periodic array configuration enhances collective plasmonic effects, resulting in uniform resonance behavior across the metamaterial surface. This work provides valuable design guidelines for tunable plasmonic metamaterials with applications in biosensing, optical detection, and nanophotonic devices.

Md Maruf Hossain, Md Fahim Razi Prantik, Md Anik Hasan Plabon, Dipayon Bachar,"Optical Characterization of Ag/ZnO Split-Rod Plasmonic Metamaterials" International Journal of Scientific Research and Engineering Development, V9(2): Page(2176-2182) Mar-Apr 2026. ISSN: 2581-7175. www.ijsred.com. Published by Scientific and Academic Research Publishing.