Direct method to control surface plasmon polaritons on metal surfaces

The manipulation of surface plasmon polaritons (SPPs) on metal surfaces is an important aspect in the design of ultra-compact integrated micro/nano optical systems. We present a direct method for the easy, yet accurate design of complicated groove patterns to control SPPs traveling on metal surfaces, using a surface electromagnetic wave holography method, based on the Huygens - Fresnel principle. SPPs are scattered by these deliberately and appropriately determined groove patterns and interfere with each other to form new paths with desire. Two devices are demonstrated, with pre-designated functionalities fully implemented by the designed plasmonic holographic structures, according to the finite-difference time-domain simulations. The results strongly indicate that this direct method is effective, efficient, and user friendly in its application to control SPPs on metal surfaces.