Concurrent Optimization of Diffraction Fields from Binary Phase Mask for Three-Dimensional Nanopatterning

Abstract

Obtaining a high resolution of a three-dimensional (3D) nanostructure is crucial in nanoengineering. For proximityfield nanopatterning (PnP), a type of nanostructure fabrication with a continuous transfer of interference, the geometry of the phase mask primarily determines the resolution of a fabricated nanostructure by modulating the phase shift of coherent lights. Currently, phase masks for PnP are limited to the intuitive design focusing on reducing zeroth (0th) order efficiency with a single variable design. Herein, the concurrent optimization method, using particle swarm optimization, calculates the optimum phase mask with an improved figure of merit for maximizing the electric field intensity contrast. For the high-contrast 3D nanopatterning, we inversely designed the desired electric-field intensity map and calculated the required phase mask. The calculated optimum phase mask for PnP fabricates the hexagonal nanochannel array with high uniformity in lattice and pore shape owing to its selective intensity control. In contrast to the minimized zeroth diffraction design, which cannot modify the intensity in a specific region, the inverse design can selectively maximize or minimize the intensity in the target regions. This concurrent optimization using the inverse design method increases the degree of freedom for the nanostructure of PnP, and it can fabricate the proper nanostructure applicable to various fields such as energy devices, structural materials, and semiconductor devices.

High‐Throughput Fabrication of Large‐Scale Metaholograms via One‐step Printing

“…In a further study, several optimization methods will be attempted to enhance the efficiency of efficient metasurfaces, resulting in the design of highly efficient metaholograms across a broader spectrum of wavelengths. [49][50][51] Furthermore, using the same stamp as above, we adopted a more productive and yield-efficient method, although it resulted in lower efficiency, to fabricate the metasurface. An 8-inch holographic film sample was obtained using a simple process shown in Figure S9 (Supporting Information), which utilizes a UVcurable resin.…”

“…In a further study, several optimization methods will be attempted to enhance the efficiency of efficient metasurfaces, resulting in the design of highly efficient metaholograms across a broader spectrum of wavelengths. [ 49–51 ]…”

Liquid crystal-integrated metasurfaces for an active photonic platform

“…The second method involves resonance effects, such as Mie resonance 31−33 , Fabry-Pérot (FP) resonance 34−36 , guided-mode resonance (GMR) 37,38 , and bound states in the continuum (BIC) resonance 39−41 . Finally, various simulation tools, such as rigorous-coupled wave analysis (RCWA) 42,43 , finite-difference time-domain (FDTD) 44−46 , and finite element methods (FEM) 47,48 can be used to optimize meta-atoms. Over the last two decades, these design methods have been employed to potentially replace conventional optical systems due to their standout features such as high numerical aperture (NA) and wide field of view (FOV).…”

Two‐Photon Polymerization Lithography for Optics and Photonics: Fundamentals, Materials, Technologies, and Applications

“…[21][22][23][24] Interference lithography also possesses similar advantages and is possible for 3D fabrication, but the pattern is not freely customized, and only limited forms of photonic crystals can be made. [25,26] 3D self-assembly assisted by nanopipette nozzle is promising for complex 3D printing, nevertheless the slow printing speed, weak mechanical stability of structures, and easy jam of the nozzle, hindering the usage for fast and multiscale fabrication. [27,28] 3D nanoprinting via charged aerosol jets is also demonstrated, making use of magnetic fields and dielectric masks to control the deposition of charged particles or ions.…”