Control surface plasmon polaritons propagation efficiently with only one holographic line

Controlling surface plasmon polaritons (SPPs) propagation on metal surface is significant for wide applications. Simple and effective structures are needed for SPP propagation controlling. In this paper, the line holography method is proposed to design a simple structure to control SPP wave propagation. The designed structure is composed of only one metal line, rather than a number of grooves in the holograms designed by the common surface electromagnetic wave holography method (SWH). The holographic line structure can control SPPs propagation effectively. Through the line holography method, two holographic line structures are designed to focus aside a plane SPP wave to one or two points. The finite-difference time-domain (FDTD) method is used to simulate the control process. Results show that the holographic line can control the SPP wave propagation with efficiency of 55%, higher than that of the common SWH method (19%).