Creating Optical Near-Field Orbital Angular Momentum in a Gold Metasurface
Ching-Fu Chen1, Chen-Ta Ku1, Ming-Yang Pan2, Pei-Kuen Wei2, Chen-Bin Huang1*
1Institute of Photonics Technologies, National Tsing Hua University, Hsinchu, Taiwan
2Research Center for Applied Sciences, Academia Sinica, Taipei, Taiwan
* presenting author:Chen-Bin Huang,
Nanocavities in a gold thin film is optimized and arranged to form a metasurface. For the first time, we demonstrate both numerically and experimentally that surface plasmon vortex carrying optical orbital angular momentum can be generated using linearly-polarized optical excitation.

Keywords: Plasmonics, Optical angular momentum, Vortex, Metasurface