Park Jusung, Park Seungkyun, Kim Kyuho, Kwak Jeonghun, Yu Sunkyu, Park Namkyoo
Photonic Systems Laboratory, Department of Electrical and Computer Engineering, Seoul National University, Seoul 08826, Korea.
Intelligent Wave Systems Laboratory, Department of Electrical and Computer Engineering, Seoul National University, Seoul 08826, Korea.
Nanophotonics. 2025 Jan 7;14(8):1113-1122. doi: 10.1515/nanoph-2024-0541. eCollection 2025 Apr.
Light behaviours in disordered materials have been of research interest primarily at length scales beyond or comparable to the wavelength of light, because order and disorder are often believed to be almost indistinguishable in the subwavelength regime according to effective medium theory (EMT). However, it was demonstrated that the breakdown of EMT occurs even at deep-subwavelength scales when interface phenomena, such as the Goos-Hänchen effect, dominate light flows. Here we develop the engineering of disordered multilayers at deep-subwavelength scales to achieve angle-selective manipulation of wave localization. To examine the disorder-dependent EMT breakdown, we classify the intermediate regime of microstructural phases between deep-subwavelength crystals and uncorrelated disorder through the concept of stealthy hyperuniformity (SHU). We devise material phase transitions from SHU to uncorrelated disorder for distinct angular responses of wave localization by tailoring the short-range and long-range order in SHU multilayers. The result paves the way to the realization of deep-subwavelength disordered metamaterials, bridging the fields of disordered photonics and metamaterials.
无序材料中的光行为主要在超过或与光波长相当的长度尺度上受到研究关注，因为根据有效介质理论（EMT），在亚波长范围内，有序和无序通常被认为几乎无法区分。然而，有研究表明，当诸如古斯 - 汉欣效应等界面现象主导光流时，即使在深亚波长尺度下，EMT也会失效。在此，我们开展了深亚波长尺度下无序多层膜的工程研究，以实现对波局域化的角度选择性操控。为了研究与无序相关的EMT失效情况，我们通过隐身超均匀性（SHU）的概念，对深亚波长晶体和不相关无序之间的微观结构相的中间区域进行分类。我们通过调整SHU多层膜中的短程和长程有序，设计了从SHU到不相关无序的材料相变，以实现波局域化的不同角度响应。这一结果为实现深亚波长无序超材料铺平了道路，架起了无序光子学和超材料领域之间的桥梁。
