Related Experiment Video
Updated: Apr 15, 2026

Fabrication and Operation of a Nano-Optical Conveyor Belt
Published on: August 26, 2015
Creating optical near-field orbital angular momentum in a gold metasurface
Ching-Fu Chen1, Chen-Ta Ku1, Yi-Hsin Tai2
1†Institute of Photonics Technologies, National Tsing Hua University, Hsinchu 30013, Taiwan.
Abstract:
Nanocavities inscribed in a gold thin film are optimized and designed to form a metasurface. We demonstrate both numerically and experimentally the creation of surface plasmon (SP) vortex carrying orbital angular momentum in the metasurface under linearly polarized optical excitation that carries no optical angular momentum. Moreover, depending on the orientation of the exciting linearly polarized light, we show that the metasurface is capable of providing dynamic switching between SP vortex formation or SP subwavelength focusing. The resulting SP intensities are experimentally measured using a near-field scanning optical microscope and are found in excellent quantitative agreements as compared to the numerical results.
Related Concept Videos
Angular Momentum
Conservation of Angular Momentum: Application
Angular Momentum about an Arbitrary Axis
The velocity of a mass element comprises its translational velocity and the relative velocity instigated by the body's rotation. Substituting the velocity equation into...
Angular Momentum: Single Particle
Conservation of Angular Momentum
Atomic Nuclei: Larmor Precession Frequency

