Superlensing plano-convex-microsphere (PCM) lens for direct laser nano-marking and beyond

Abstract

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 µ m 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 next-generation low-cost direct laser nano-marking machine and super-resolution imaging nanoscope.

Wavelength‐Scale Photonic Space Switch Proof‐Of‐Concept Based on Photonic Hook Effect

“…Worthwhile noting, due to the simple design of the wavelength‐scaled switching element (a DOE), the high‐precision 3D printing technologies such as TPP and SLA [ 24,25,27,28 ] can be used to manufacture the considered mesoscale elements operating in the optical or THz spectral ranges. [ 29 ]…”

“…Besides, the above photonic space switches could be fabricated using two photon polymerization (TPP) 3D printing and plano‐convex‐microsphere (PCM) lens laser nano marking technologies. [ 24,25 ] TPP 3D printing is a technique to additively fabricate micro/nano features relying on the two‐photon absorption process triggered by a focused femtosecond (fs) laser. Using this method, solidification of photoresist only occurs at the laser focus, which results in the micro/nanosized photonic wires along the laser scanning path and then DOEs, for example, prisms and Janus bar, can be created layer by layer in an additive way with high precision and a high degree of design freedom.…”

Generation of Photonic Hooks from Patchy Microcylinders

“…As shown in Figure 1b, an intense focusing of light will occur on the rear side of the cylinder when a P-polarized monochromatic plane wave (λ = 550 nm) propagating parallelly to the X axis passes through the cylinder. In this study, the RI of the cylinder is set to be 1.9, the same as the RI of BaTiO 3 (BTG), a high-index dielectric material widely used in microsphere-based applications [3,9]. The diameter of the cylinder varies between 1-35 µm and the RI of the background changes between 1.00-1.52.…”

“…They can propagate a distance longer than the wavelength of the incident light while keeping a minimum beamwidth smaller than λ/2, λ is the wavelength of the incident light [2]. PJs show promising applications in various fields, such as micromaching [3], single-particle manipulation [4], optical sensing [5,6], super-resolution imaging [7][8][9][10], and so forth. Within this context, many efforts have been made to design dielectric particles that can generate PJs with special characteristics [11,12].…”

Super-Resolution Imaging with Patchy Microspheres

“…Moreover, samples may be contaminated or even damaged in liquid. Only a small amount of research has been done to improve the imaging performance of microspheres in air, such as improving illumination conditions [5], optimizing the diameter and the refractive index of microspheres [18], using plano-convexmicrosphere (PCM) lens design [19,20], and using a microsphere lens group [21].…”