Figure 3
Diffraction pattern measured for a sample (3 × 3 hexagonal array) in the presence of an amplifier (concentric ring structure). The corresponding SEM is shown in the upper left. The ring along the blue contour is remapped to a (average-subtracted) one-dimensional curve versus ϕ (top right). The first- and second-order angular correlations are plotted in the lower-right figure. The first-order correlation (red) is flat and noisy. However, the second-order correlation function (magenta) closely matches the idealized expectation for the known sample symmetry (blue). The interference fringes oscillate as the inverse sample–amplifier distances ≃ 2π/1 µm ≃ 6 × 10−4 Å−1. |