标题： 通过空间折叠实现超宽带光学零介质的实施 显示英文标题

标题： Implementation of ultra-broadband optical null media via space-folding

摘要： 光学零介质（ONM）在电磁波操控方面引起了广泛关注。然而，现有的ONM实现要么操作带宽狭窄，要么效率低下。在这里，我们展示了一种超宽带ONM设计，同时解决了这两个挑战——实现了宽带操作并且与空气保持完美的阻抗匹配，从而实现近似单位的透射率。所提出的折叠空间ONM通过在金属通道阵列中引入精确设计的折叠结构来实现，创建了一个有效的无色散介质，能够在每个通道中独立控制相位。该设计包含了通过逐渐渐变折叠结构实现的优化边界层，实现了与周围介质的完美阻抗匹配。实验验证了束弯曲效应和宽带束聚焦效应。由于其简单的材料要求、宽带特性和高透射率，所提出的折叠空间ONM在电磁隐身、束转向装置和超紧凑微波组件等方面显示出潜在应用价值。 显示英文摘要

摘要： Optical null medium (ONM) has garnered significant attention in electromagnetic wave manipulation. However, existing ONM implementations suffer from either narrow operational bandwidths or low efficiency. Here, we demonstrate an ultra-broadband ONM design that simultaneously addresses both challenges - achieving broad bandwidth while preserving perfect impedance matching with air for near-unity transmittance. The proposed space-folding ONM is realized by introducing precisely engineered folds into a metal channel array, creating an effective dispersion-free medium that enables independent phase control in each channel. The design incorporates optimized boundary layers implemented through gradually tapered folding structures, achieving perfect impedance matching with the surrounding medium. Beam bending effect and broadband beam focusing effect are experimentally verified using the proposed space-folding ONM. Due to its simple material requirements, broadband characteristics, and high transmittance, the proposed space-folding ONM shows potential for applications in electromagnetic camouflage, beam steering devices and ultra-compact microwave components.