Surface plasmon polaritons interference excited by a tightly focused and radially polarized vortex beam

A tightly focused and radially polarized vortex beam can not only provide a wider angular spectrum and a stronger longitudinal electric field in the process of surface plasmon polaritons (SPPs) interference, but also avoid the influence of the center angular spectrum on the main peak of the SPPs interference field. In this paper, we focus on a case of a SPPs standing field induced by a tightly focused and normally incident radially polarized vortex beam and compare it with that resulting from radially polarized Gaussian beam and linear polarized vortex beam. At the present time, the photonic nano-devices based on the SPPs are considered to be the basic of all-optical integrated loop with nanometer scale. So the study of the properties of the SPPs standing field is very important and some factors on the generation of interference pattern is considered and analyzed.