Figure 3: Spectral response of the symmetric superlens.
From: Near-field examination of perovskite-based superlenses and superlens-enhanced probe-object coupling
Near-field spectra as well as near-field images and NF3Ω-distance curves for selected wavelengths (scale bars, 10 μm). (a) For λ=13.9–15.9 μm, an imaging contrast exists because of the localized polariton mode. (b) Shows the near-field spectrum for a fixed distance of z=20 nm with the results between 13.5 and 16.25 μm being multiplied by a factor of four in the plot. (c) For λ=16.8–18.4 μm, no imaging contrast is observed although the near-field signal is enhanced by the non-localized polariton mode. The red and green curves in the distance curves of a, c and the spectrum b correspond to the near-field signals on areas with and without SrRuO3 objects on the opposite side of the lens, respectively.
