Graphene nanoridges as a directional plasmon launcher

摘要

Launching and control of graphene plasmon are crucial for nanodevice applications. To achieve that, previous studies used foreign object and/or angled illumination to provide plasmon launching and directional control. In this study, we considered graphene nanoridges, which is a defect-free natural structure of graphene to launch plasmon, using analytic method and simulation. The result shows that a single graphene nanoridge can launch plasmon, with an interesting relationship between the SPP amplitude and ridge physical curve length. By using two nanoridges with different size, the interference between SPP wave launch from each ridge result in right-left asymmetric plasmon launching. With the proper size and separation, unidirectional, bidirectional, or wavelength-sorted plasmon launching can be achieved.