Fig. 5: Second harmonic generation (SHG) of circular and triangular hole metasurfaces.
From: Ultrathin 3R-MoS2 metasurfaces with atomically precise edges for efficient nonlinear nanophotonics
a Circular hole metasurface SHG enhancement, SHGmeta/SHGflake, vs. pump wavelength λpump. The pump polarization is linear along the y-axis. Detection has no analyzer. Circles correspond to experimental data, while the shaded area to numerical simulations. The inset depicts an atomic force microscopy (AFM) scan of the metasurface. b Triangular hole metasurface SHG enhancement, SHGmeta/SHGflake, vs. the pump wavelength. The pump polarization is linear along y-axis. Detection has no analyzer. Triangles correspond to experimental data, while the shaded area to numerical calculations in Comsol. The inset depicts an AFM scan of the metasurface. The error bars in (a) and (b) are less than the marker sizes. c Numerical (calc) - (i, iii) - and experimental (exp) - (ii,iv) polar plots of the SHG intensity (i, ii) and SHG enhancement (ratio of metasurface-to-flake SHG; iii,iv)) for the circular hole metasurface. SHG intensity (i,ii) is plotted in a linear scale. SHG enhancement (ratio; iii, iv) is plotted in a log-scale. The shaded background is the AFM image of the metasurface aligned with the polarization angles. d Numerical (calc) - (i, iii) and experimental (exp) - (ii, iv) polar plots of the SHG intensity (i, ii) and SHG enhancement (ratio of metasurface-to-flake SHG; iii, iv) for the triangular hole metasurface. SHG intensity (i, ii) is plotted in a linear scale. SHG enhancement (ratio; iii, iv) is plotted in a log-scale. The shaded background is the AFM image of the metasurface aligned with the polarization angles. Paramaters of the numerical calculation are the same as in Figs. 3 and 4.
