Subwavelength light focusing of plasmonic lens with dielectric filled nanoslits structures

作者：Hao Wang, Yongqiang Deng, Jiayu He, Ping Gao, Na Yao, Changtao Wang, Zeyu Zhao, Jiong Wang, Bo Jiang, Xiangang Luo · 发表于：Journal of Nanophotonics · 年份：2014 · DOI：10.1117/1.jnp.8.083079 · 被引用次数：11 · 研究领域：Plasmonic and Surface Plasmon Research、Near-Field Optical Microscopy、Optical Coatings and Gratings

A plasmonic lens composed of a dielectric-filled nanoslits structure on an aluminum film is proposed and experimentally demonstrated. The slits’ structure is designed with equal distance, length, and width, but filled with variant thickness SiO2 dielectric for specific phase retardations. A dual focused ion beam instrument is employed to mill the slits and deposit SiO2 into the slits. The phase modulation by SiO2-filled slits is illustrated by a double slits interference experiment. The light focusing behavior of the fabricated plasmonic lens is experimentally characterized by a scanning near-field optical microscope. Experimental results show good agreement with the simulations.