Fig. 2: Aliasing in 1D beam steering metasurface.
a Schematic illustration of 1D metasurface and reproduced light cones in the momentum space. The spectral range where aliasing occurs can be obtained from overlapping light cones. Depending on the target frequency of light (ω0) and the sampling interval (Λ), the range of overlap spectral region is determined. b The cross-section of light cones at the target frequency. Depending on the magnitude of the encoded momentum ( | kmeta | ), the normally incident light can couple not only the 0th-order light cone but also the adjacent higher-order light cone. c–e Calculated diffraction efficiency for various sampling levels where (c) λ/Λ = 2.04, (d) λ/Λ = 1.82, (e) λ/Λ = 1.61, respectively. Yellow, red, and blue colors in the graphs represent the three diffraction regimes, AF, WW, and SW regimes, respectively.
