摘要

Due to the coupling effect of SPPs excited by the incident electromagnetic field, the metallic nanorods structures show special optical properties that can be applied in many fields of nano-technology. The excitation efficiency spectrums of the two parallel nanorods and the pi-shaped nanorods structures are calculated by FDTD method, respectively, which show different SPR peak positions under the same conditions for these two structures. The high numerical aperture focusing processes through these two structures are simulated by 3D FDTD method. The results show that the pi-shaped nanorods perform better electromagnetic field far field transfer efficiency than the two parallel nanorods. Finally the focusing process through the angular pi-shaped nanorods structure is investigated, which indicates that the focal field can be transferred to different directions away from the optical axis of the focal beam.