Figure 2
From: Increasing efficiency of high numerical aperture metasurfaces using the grating averaging technique
(a) Schematic of a periodic metasurface based on the grating averaging design. Simulated transmission data for different nano-post widths W is also shown. (b) Design curve relating the desired phase to the nano-post width for the metasurface design shown in (a) and the corresponding transmittance. The design curve is obtained using the transmission data shown in (a). (c) Diffraction efficiencies of the third transmitted order of blazed gratings with different phases (ϕg). The blazed gratings are designed using the metasurface platform and design curve shown in (a and b). The gratings’ period is 3500 nm (i.e., ten times the metasurface lattice constant) corresponding to a third order diffraction angle of 51.7°. The efficiency values are computed for light normally incident from the substrate with transverse electric (TE) and transverse magnetic (TM) polarizations. (d) Estimated deflection efficiencies of beam deflectors implemented using the metasurface design shown in Fig. 1 and the grating averaging design shown in (a and b).
