Generation of Switchable Singular Beams with Dynamic Metasurfaces.

Area of Science:

• Optics and Photonics
• Materials Science
• Nanotechnology

Background:

• Singular beams are crucial for light manipulation and optical communications.
• Existing methods lack practical, sub-wavelength resolution for switchable singular beams using ultrathin devices.

Purpose of the Study:

• To demonstrate switchable vector and vortex beams using dynamic metasurfaces.
• To achieve sub-wavelength resolution with ultrathin, flat optical devices.
• To explore applications in optical communications and anti-counterfeiting.

Main Methods:

• Utilized dynamic metasurfaces with magnesium nanorods at visible frequencies.
• Leveraged plasmonic reconfigurability of nanorods via hydrogenation/dehydrogenation.
• Implemented a two-cascade metasurface scheme for holographic pattern switching.

Main Results:

• Successfully generated switchable vector beams with varying polarization states.
• Demonstrated switchable vortex beams with different topological charges.
• Showcased holographic pattern switching inspired by orbital angular momentum-shift keying.

Conclusions:

• The developed dynamic metasurfaces offer a practical route to switchable singular beams.
• This technology enables tunable optical elements with sub-wavelength resolution.
• The work opens avenues for high-security optical elements and advanced optical communications.