%A Yan DENG, Jian OU, Jiangying YU, Min ZHANG, Li ZHANG %T Coupled two aluminum nanorod antennas for near-field enhancement %0 Journal Article %D 2017 %J Front. Optoelectron. %J Frontiers of Optoelectronics %@ 2095-2759 %R 10.1007/s12200-017-0663-2 %P 138-143 %V 10 %N 2 %U {https://journal.hep.com.cn/foe/EN/10.1007/s12200-017-0663-2 %8 2017-07-05 %X

Aluminum (Al) plasmonic nanoantennas possess many tunabilities in the ultraviolet (UV) region and have a variety of new applications, such as in sensitive UV photodetection and UV photolithography. Using discrete dipole approximation (DDA), the resonant optical properties and enhanced local field distribution of coupled Al nanorod antennas were investigated. The effects of gap distance on the extinction spectra were analyzed to obtain the surface plasmon modes of these nanostructures across the visible and in the UV spectral range, which can be attributed to the coupling of the surface plasmon modes from each Al nanorod. In addition, the enhanced local field factors plotted as a function of gap distance were simulated under transverse and longitudinal polarizations to achieve maximum near-field enhancement for the optical antennas. When the gap distance was decreased to 5 nm, the maximum value of the enhanced factor was 18.04 at the transverse mode peak of 424 nm. This could be explained by the combination of the interaction between the charges distributed at the opposite ends of two Al nanorods and the interaction between the charges distributed at the lateral sides of each Al nanorod. Results showed that the coupled Al nanorod antennas with enhanced local field show promise for UV plasmonics.