Superlensing Plano-Convex-Microsphere(PCM) lens for direct laser nano marking and beyond

A high-performance all-dielectric lens, formed by integrating a conventional plano-convex lens with a high-index
microsphere lens (PCM), was developed for far-field
super-resolution applications. The PCM lens features a
theoretical resolution of ∼ λ/2.5 in air with a WD ∼ 2 µm
away from the lens. When combined with a femtosecond
laser, the actual patterning resolution can reach ∼ λ/3.5.
The unusual focusing properties were theoretically and
experimentally verified, and direct laser nano-writing of
arbitrary patterns and nanostructures on various substrates
was demonstrated. This Letter can be naturally extended
to other super-resolution applications, including imaging,
sensing, and trapping, with the potential of developing nextgeneration low-cost direct laser nano-m