Optical spin-to-orbital angular momentum conversion in structured optical fields
Zhao Yang1, Yang Cheng-Xi1, Zhu Jia-Xi1, Lin Feng1, †, Fang Zhe-Yu1, 2, 3, 4, ‡, Zhu Xing1, 2, 4
       

The Ag NPs on the middle of NW are ellipsoids. (a1), (b1), (c1), and (d1) are four different ellipsoids, with the three semi-axes labeled on each ellipsoid, the unit is nm. (a2), (b2), (c2), and (d2) show the direction of PO relative to the Ag NW axis. The color in the Ag NW represents the electric field of SPPs propagating along the NW.