Large-Angle, Multifunctional Metagratings Based on Freeform Multimode Geometries

We show that silicon-based metagratings capable of large-angle, multifunctional performance can be realized using inverse freeform design. These devices consist of nonintuitive nanoscale patterns and support a large number of spatially overlapping optical modes per unit area. The quantity of modes, in combination with their optimized responses, provides the degrees of freedom required to produce high-efficiency devices. To demonstrate the power and versatility of our approach, we fabricate metagratings that can efficiently deflect light to 75° angles and multifunctional devices that can steer beams to different diffraction orders based on wavelength. A theoretical analysis of the Bloch modes supported by these…

• NS
  National Science Foundation
• UD
  U.S. Department of Defense
• AP
  Alfred P. Sloan Foundation
• OO
  Office of Naval Research

  Award: N00014-16-1-2630
• AF
  Air Force Office of Scientific Research

  Award: FA9550-15-1-0161