(a) Schematic and (b) cross-section of the NPoM plasmonic system comprising a gold nanowire array supported by an ITO film on top of a gold substrate; (c) Real (red line) and imaginary (cyan line) parts of the ITO film described with the Drude model; (d) Reflectivity of a bare ITO film on a gold substrate (red line), a bare NPoM system (blue line), and an NPoM system with an ITO film as the spacer (green line), where the illustration shows the linear near-field intensity |E| at the ENZ wavelength. For all three structural configurations, the period T is 100 nm, the ITO thickness d and air gap are 1 nm, and the nanoparticle diameter D is 20 nm. The angle of incidence is π/4.