Fabricable concentric-ring metalens with high focusing efficiency based on two-dimensional subwavelength unit...

Area of Science:

• Optics and Photonics
• Materials Science

Background:

• Developing large-aperture metalenses faces challenges in computational resource consumption and data volume.
• Existing methods may not efficiently handle the complexities of metalens design for various applications.

Purpose of the Study:

• To propose a novel design method for concentric-ring metalenses that addresses computational and data challenges.
• To enable the development of polarization-insensitive metalenses with high focusing efficiency.

Main Methods:

• A design method based on two-dimensional unit splicing for concentric-ring metalenses.
• Construction of a unit structure library through global traversal under machining constraints.
• Phase matching for two polarization states with specific weights to achieve arbitrary polarization sensitivity.

Main Results:

• Achieved focusing efficiency up to 90% for binary-height, concentric-ring structures.
• Developed a polarization-insensitive metalens (10µm wavelength, 2cm diameter, 0.447 NA).
• Reduced calculation and processing costs by several orders of magnitude for large-diameter metalenses.

Conclusions:

• The proposed method significantly lowers computational and data requirements for metalens development.
• The method allows for high focusing efficiency, approaching theoretical limits.
• This approach facilitates the practical development of advanced metalenses for diverse applications.