Polarization-controllable perfect vortex beam by a dielectric metasurface

Area of Science:

• Optics and Photonics
• Metamaterials
• Beam Shaping

Background:

• Perfect vortex beams are of great interest due to their unique properties, such as a radius independent of topological charge.
• Existing methods for generating these beams can be complex or lack tunability.

Purpose of the Study:

• To propose and demonstrate a novel method for generating perfect vortex beams using propagation-phase-based dielectric metasurfaces.
• To achieve efficient and controllable generation of dual perfect vortex beams from a single metasurface.

Main Methods:

• Utilized the superposition principle of phase in Fourier space.
• Designed and fabricated a propagation-phase-based dielectric metasurface.
• Exploited the polarization sensitivity of the propagation phase to impose dual phase profiles.

Main Results:

• Achieved a production efficiency greater than 83.5% for perfect vortex beams.
• Demonstrated simultaneous generation of dual perfect vortex beams with low crosstalk (<4%).
• Enabled convenient control over beam radius and topological charge by switching incident polarization.

Conclusions:

• The proposed propagation-phase metasurface method offers an efficient and versatile approach for generating perfect vortex beams.
• This technique facilitates independent control of dual beams, paving the way for advanced optical applications.
• Potential applications include optical communication, particle manipulation, and holographic displays.