Plasmonic polarization nano-splitter based on asymmetric optical slot antenna pairs

We propose and experimentally demonstrate a plasmonic polarization nano-splitter composed of asymmetric optical slot antenna pairs. Broadband polarization-controlled unidirectional surface plasmon polariton (SPP) launching and splitting are achieved experimentally using an asymmetric optical slot antenna pair array. Both transverseelectric and transverse-magnetic-polarized incident light is coupled to SPPs on the metal surface, but with opposite directions. The measured extinction ratio for the two opposite propagating directions is larger than 5 dB within a bandwidth of 160 nm and reaches up to similar to 12 dB at an incident wavelength of 790 nm. This plasmonic polarization nano-splitter, together with the polarization-controlled unidirectional SPP coupler, may have promising applications in the nano-optics and integrated optical circuits. (C) 2016 Optical Society of AmericaNational Natural Science Foundation of China (NSFC) [11404012, 61377050, 11574011]; Research Fund for the Doctoral Program of Higher Education [20130001110050]SCI(E)ARTICLEjingyang@pku.edu.cn; jszhang@pku.edu.cn214931-49344