Light‐Controlled Fabrication of Disordered Hyperuniform Metasurfaces

Abstract

Disordered hyperuniformity (DHU) is one of the most prominent manifestations of the engineered disorder, which aims to circumvent limitations commonly related to order. Considering the k‐space, isotropic DHU is characterized by an isotropic suppression of scattering for wavenumbers k approaching zero. Thereby, stealthy DHU is a particularly strong form of DHU, where scattering is even suppressed for wavenumbers 0 < k ≤ K within a circular window of radius K. Although experimental demonstrations of DHU in optical structures exist, scalable and low‐cost fabrication methods are still rare and often lack the opportunity for in‐situ control of the k‐space. Here, a novel and facile bottom‐up approach for the fabrication of DHU metasurfaces is presented. Starting with a solution‐based deposition procedure of silver nanoparticles (AgNPs) in darkness (resulting in DHU), a more extensive way of in‐situ k‐space engineering is introduced by illuminating the growing metasurface with light (resulting in stealthy DHU). While it is shown that the wavelength of incident light allows for the in‐situ control of K, its lateral momentum k∥ defines an additional design parameter. The light‐controlled growth under maximum k∥ via surface plasmon polaritons enables the experimental confirmation of the theoretically predicted phenomenon of anisotropic stealthy DHU.

Harnessing Short-Range Surface Plasmons in Planar Silver Films via Disorder-Engineered Metasurfaces

“…However, features of engineered disorder, e.g., disordered hyperuniformity, have recently been found in metasurfaces fabricated with the method presented here. 19 A well-established method to investigate the morphology of metasurfaces is given by the Fourier transform. 20 , 21 In Figure 1 c, a typical Fourier-transformed electron micrograph (FTEM) of the metasurface is shown.…”

Topological Learning for the Classification of Disorder: An Application to the Design of Metasurfaces

“…In order to circumvent such limitations, significant effort has been devoted to devise quicker and cheaper fabrication techniques, which led to some successes, but usually at the cost of emerging structural disorder. Such examples include gas-phase cluster beam deposition, nanosphere photolithography, or lithography-free fabrication methods, such as bottom-up self-assembled systems, − colloid deposition, or polymer phase separation. − …”