Three-dimensional (3D) nanoscale focusing of radially polarized light in far field by a simple plasmonic lens composed of an annular slit and a single concentric groove is reported. The numerical calculations reveal that the incident light is coupled to surface plasmon polaritons (SPP) by the annular slit and a focal spot with a size less than a half of the illumination wavelength is formed in the far field due to the constructive interference of the scattered light by the groove. More importantly, the focal length can be modulated by changing the groove diameter. This structure provides an admirable choice for the nano-optical devices. (C) 2010 Optical Society of America
1.Chinese Acad Sci, Inst Opt & Elect, State Key Lab Opt Technol Microfabricat, Chengdu 610209, Peoples R China 2.Sichuan Univ, Dept Phys, Chengdu 610064, Peoples R China 3.Swinburne Univ Technol, Fac Engn & Ind Sci, Ctr Microphoton, Hawthorn, Vic 3122, Australia 4.Swinburne Univ Technol, Fac Engn & Ind Sci, CUDOS, Hawthorn, Vic 3122, Australia
Zhang, Maoguo,Du, Jinglei,Shi, Haofei,et al. Three-dimensional Nanoscale Far-field Focusing of Radially Polarized Light by Scattering the SPPs with an Annular Groove[J]. OPTICS EXPRESS,2010,18(14):14664-14670.