(color online) All-dielectric TiO₂ mSIL. (a) Schematic of fabricated half-spherical and super-spherical mSIL. (b) Plane wave (λ = 550 nm) passing through the stacked TiO₂ nanoparticles. Electric field hot spots are generated in gaps between contacting particles, which guide light to the underlying sample. (c) Large-area nanoscale evanescent wave illumination that can be focused onto the sample surface because of the excitation of nano-gap mode. (d) Size of illumination spots, which is equal to particle size and has FWHM resolution of ∼8 nm. (e) SEM image of a wafer pattern with 100 nm pitch size and its optical microscopy image with TiO₂ mSIL with magnification factor 3.0. (f) SEM image of wafer pattern with 90 nm pitch size after being gold-coated and its optical microscopy image with TiO₂ mSIL with magnification factor 3.1. Reproduced with permission from Ref. [41].