Super resolution from pure/hybrid nanoscale solid immersion lenses under dark-field illumination.

We report a super-resolution strategy based on pure/hybrid nanoscale solid immersion lenses (n-SILs) under dark-field illumination. Dependences of the focusing performance of pure n-SILs on different diameters, locations, and substrates are investigated. Simulation results demonstrate a higher resolution (up to a 22.8% improvement) of pure n-SILs under dark-field illumination than convergent plane wave illumination. A hybrid n-SIL with a higher-index nanorod embedded into the n-SIL is proposed. Under dark-field illumination, the hybrid n-SIL can generate a near-field focal spot with a much higher resolution (~λ/8) that is beyond the Abbe diffraction limit in the nanorod. These results have potential applications in data storage, near-field mapping and spectra, and nanoscale lithography.