Volumetric Nonlocal Metasurface for Electromagnetic Wave Mapping

The patent transitions from conventional 2D metasurface structures to a 3D volumetric metasurface configuration. This dimensional expansion enables nonlocal optical processing by allowing electromagnetic waves to interact with the metasurface structure through its entire volume, not just at the surface plane. The volumetric arrangement of high-index dielectric elements provides additional spatial degrees of freedom for controlling wave propagation and achieving complex optical functions that were previously impossible with planar metasurfaces.

The patent employs parameter optimization in the design of volumetric metasurface elements, specifically adjusting the size, shape, and spacing of high-index dielectric structures to achieve desired nonlocal optical responses. By carefully controlling geometric parameters and material properties, the patent enables fabrication using standard semiconductor manufacturing techniques such as electron-beam lithography and reactive ion etching, thereby managing manufacturing complexity while achieving advanced optical functionality.

The patent implements local quality variation by using high-index dielectric materials with specific refractive indices tailored for different regions or functions within the volumetric metasurface. Different material compositions or densities are employed at different locations to optimize local optical responses while maintaining overall nonlocal processing capability. This approach allows precise control of wave manipulation at specific positions without requiring uniform ultra-high precision throughout the entire structure.