High-efficiency, large-area, topology-optimized metasurfaces.

Area of Science:

• Optics
• Materials Science
• Computational Science

Background:

• Metasurfaces are ultrathin optical elements offering potential for compact and lightweight optical systems.
• Maximizing metasurface efficiency is crucial for practical applications.
• Current topology optimization methods for metasurfaces are computationally intensive, limiting designs to microscale devices.

Purpose of the Study:

• To introduce a computationally efficient strategy for optimizing large-area metasurfaces.
• To overcome the limitations of existing topology optimization methods for large-scale metasurface design.

Main Methods:

• A novel strategy of stitching individually optimized sections to create large-area metasurfaces.
• Reducing computational complexity from high-polynomial to linear through sectional optimization.
• Experimental demonstration of large-area, high-numerical-aperture silicon metasurface lenses.

Main Results:

• Achieved focusing efficiencies exceeding 90% for large-area metasurface lenses.
• Demonstrated a computationally efficient method for large-area metasurface optimization.
• Successfully designed and fabricated high-performance silicon metasurface lenses.

Conclusions:

• The proposed sectional optimization and stitching strategy enables efficient design of large-area metasurfaces.
• This approach overcomes computational barriers, paving the way for practical implementation of advanced metasurface devices.
• The methodology can be extended to multifunctional, broadband diffractive optical devices.