Description
3D metallic structures with symmetrically curved surfaces are proposed for surface plasmon polaritons (SPPs) deflection and concentration. Two-photon polymerization (2PP) and a sputtering process are applied for the preparation of the proposed structures. Leakage radiation microscopy (LRM) is used for the excitation and observation of SPPs. The characterization results reveal that the proposed structures are able to deflect SPPs and partly concentrate SPPs energy when the surface waves propagate around the raised part of the metallic structure. The maximum electromagnetic energy concentration can be reached when SPPs propagate towards the center of the raised part of the structure. An investigation on the energy concentration performance of the proposed metallic structures with respect to different profiles is analytically and experimentally carried out. Applications of plasmonic devices for energy harvesting elements, omnidirectional light absorbers, and benders are discussed.