Effects Of Shape Of Terminus On Excitation Of Surface Plasmon Modes On Metal Nanowires

At present, the rapid development of the surface plasmon optics helps people have a deep understanding of a large numbers of phenomena about surface Plasmon polariton (SPP), and also enhance the control ability of light in the field of nanotechnology. However, there isn’t a detailed analysis about the specific modes of the surface plasma wave which transmit on the metal nanowire. The effects of shape of nanowire terminus on the excited SPP modes are investigated. The conical terminus and terminus cut at certain angle are studied respectively. For the first time the quantitative mode decompositions are carried out to derive the full information of excited SPP modes. It is demonstrated that the tuning of shape of terminus provides an effective method to control the composition of excited SPP modes on metal nanowires. Especially it is found that some important patterns such as the pure TMo mode and the superposition of TMo and HE+1or HE-1modes can be generated by some specific shapes of terminus, whereas there is no way to produce these patterns with flat-end nanowires.