https://www.seas.harvard.edu/news/2017/11/strange-new-world-of-light
There's a very cool image of the corkscrew effect at the link provided.
The new metasurface connects two aspects of light, known as orbital angular momentum and circular polarization (or spin angular momentum). Polarization is direction along which light vibrates. In circularly polarized light, the vibration of light traces a circle. Think about orbital angular momentum and circular polarization like the motion of a planet. Circular polarization is the direction in which a planet rotates on its axis while orbital momentum describes how the planet orbits the sun.
The fact that light can even carry orbital momentum is a relatively recent discovery — only about 25 years old — but it’s this property of light which produces strange new states, such as beams in the shape of corkscrews.
There's a very cool image of the corkscrew effect at the link provided.