Manipulating Surface Plasmon Polaritons Using F-Shaped Nanoslits Array

F-shaped nanoslits were arranged linearly and circularly to manipulate surface plasmon polaritons (SPPs) using circular polarization illumination. Numerical calculations show that when F-shaped nanoslits are linearly arranged, the electric field distribution follows unidirectional stripe-shaped patterns. Focusing is observed with a circular arrangement of the nanoslits under circular polarization illumination with specific handedness. For the latter geometry, electric fields are greatly enhanced and converge to inside the circle. These results are relevant for the design of nanophotonic devices with applications sensitive to polarization, focusing SPPs, and generating large electric fields.