| Negative index metamaterials composed of gold nanoclusters at visible and NIR frequencies |
| Paper ID : 1373-UFGNSM-FULL |
| Authors: |
|
Maryam Gholami *1, saeed Golmohammadi2 1Department of Photonics Engineering,School of Engineering-Emerging Technologies, University of Tabriz,29bahman Blvd,Tabriz,East Azarbayjan,Iran
Postal Code:
5166616471 2School of Engineering-Emerging Technologies, University of Tabriz,Tabriz,Iran |
| Abstract: |
| Metamaterials provide a path to create materials that possess a negative refractive index and suggest so many exciting new applications for manipulating light. However, the inherent and strong energy dissipation in metals is one of the major limitations that influences the performance of all NIM applications. So the reduction of losses with optimized structures seems to be an important progress. The optical properties and spectral response of a metamaterial structure were examined in this study. Our structure is made up of symmetric nanoclusters of ring/disk Au nanocavities in a periodic array. A number of different structures were studied and best results for each frequency range were achieved at specific dimensions. We first calculated and then plotted the scattering cross-sectional profile for the structure in the presence of a two different hosts, and then, measured the negative refractive-index numerically. We also tuned and induced the Fano dip in different ranges of spectrum by tuning the geometrical sizes of the structure. According to numerical calculations, we could observe a sharp fano dip with high calculated figure of merit for the clusters surrounded by a SiO2 host at λ ̴ 1500nm (NIR spectrum) and λ ̴ 600nm (visible spectrum). These results have been found using the finite difference time-domain (FDTD) simulation method. In conclusion, we can change and control the negative-refractive-index metamaterial’s working bandwidth by changing the structural parameters of the clustures. Also, it is possible to increase the efficiency of the structure by applying methods to decrease losses. This study shows a path to achieve a method to employ ring/disk nanocavities as a NIM metamaterial in designing accurate sensing devices and biochemical sensors based on the localization of surface plasmon resonsances. |
| Keywords: |
| Negative index metamaterials, nanoclusters, Fano resonance, FDTD method, surface plasmon resonsances |
| Status : Paper Accepted (Poster Presentation) |
