Being invisible ad libitum has long captivated the popular imagination, particularly in terms of safeguarding modern high-end instruments from potential threats. Decades ago, the advent of metamaterials and transformation optics sparked considerable interest in invisibility cloaks, which have been mainly demonstrated in ground and waveguide modalities. However, an omnidirectional flying cloak has not been achieved, primarily due to the challenges associated with dynamic synthesis of metasurface dispersion. We demonstrate an autonomous aeroamphibious invisibility cloak that incorporates a suite of perception, decision, and execution modules, capable of maintaining invisibility amidst kaleidoscopic backgrounds and neutralizing external stimuli. The physical breakthrough lies in the spatiotemporal modulation imparted on tunable metasurfaces to sculpt the scattering field in both space and frequency domains. To intelligently control the spatiotemporal metasurfaces, we introduce a stochastic-evolution learning that automatically aligns with the optimal solution through maximum probabilistic inference. In a fully self-driving experiment, we implement this concept on an unmanned drone and showcase adaptive invisibility in three canonical landscapes—sea, land, and air—with a similarity rate of up to 95%. Our work extends the family of invisibility cloaks to flying modality and inspires other research on material discoveries and homeostatic meta-devices.

为提高太赫兹光电导天线输出效率，提出了一种基于层级人工等离激元结构的光电导天线的设计方法。层级人工等离激元结构由纳米尺度金属块阵列和微米尺度周期栅格结合而成，理论与仿真结果表明，前者通过人工局域表面等离激元谐振效应可提高光子-电子转换效率，后者则利用人工表面等离激元结构基模的禁带和高阶模式与电流源模式之间的正交性增强了光电导天线的垂直方向性。集成了层级人工等离激元结构的光电导天线结合了两种结构的优点，数值计算结果表明，其输出效率优于分别采用两种结构的方案。相较于未改进的光电导天线，层级人工等离激元结构在较宽频带范围内（0.86~1.51 THz）实现了光电导天线垂直方向辐射功率密度的提高。

耐高温陶瓷材料氧化钇部分稳定的二氧化锆（Yttria Partially Stabilized Zirconia，YSZ）以其优异的隔热、抗高温氧化等特性，近年来在核电**、航空航天等领域得到关注。本研究基于计算流体动力学（Computational Fluid Dynamic，CFD）方法，建立了关于超音速喷涂（Supersonic Atmospheric Plasma Spraying，SAPS）等离子流场三维模型，分析了不同喷涂参数在拉伐尔喷嘴中产生的射流特性和飞行粒子的熔化和受力状态。当喷涂参数从71 kW降低到36 kW，喷涂功率降低了49.2%，等离子体射流的最高速度降低了8.5%，最高温度降低了22.2%；使用在线监测设备Spray Watch 2i（Osier，Finland）对飞行粒子的速度和温度进行在线实测，与模拟结果的对比表明：两者的相对误差在15%以内，模拟与试验结果得到了有效地相验证，这为核反应中的耐事故燃料包壳所需的高性能隔热涂层结构的精确控制提供理论指导。

All-optical modulators with ultrahigh speed are in high demand due to the rapid development of optical interconnection and computation. However, due to weak photon–photon interaction, the advancement of all-optical modulators is consequently hampered by the large footprint and high power consumption. In this work, the enhanced sensitivity around an exceptional point (EP) from parity-time (PT) symmetry theory is initiatively introduced into a nonlinear all-optical modulator design. Further, a non-Hermitian all-optical modulator based on PT symmetry is proposed, which utilizes the large Kerr nonlinearity from indium tin oxide (ITO) in its epsilon-near-zero (ENZ) region. The whole system is expected to operate around EP, giving rise to the advantages of nanoscale integration and large modulation depth. This presented modulator with high efficiency and high-speed all-optical control can be commendably extended to the design methodology of various nanostructures and further prompt the development of all-optical signal processing.

Unconventional Weyl points with topological charges higher than 1 can transform into various complex unconventional Weyl exceptional contours under non-Hermitian perturbations. However, theoretical studies of these exceptional contours have been limited to tight-binding models. Here, we propose to realize unconventional Weyl exceptional contours in photonic continua—non-Hermitian anisotropic chiral plasma, based on ab initio calculation by Maxwell’s equations. By perturbing in-plane permittivity, an unconventional Weyl point can transform into a quadratic Weyl exceptional ring, a type I Weyl exceptional chain with one chain point, a type II Weyl exceptional chain with two chain points, or other forms. Realistic metamaterials with effective constitutive parameters are proposed to implement these unconventional Weyl exceptional contours. Our work paves a way toward exploration of exotic physics of unconventional Weyl exceptional contours in non-Hermitian topological photonic continua.

The in-plane negative refraction of high-momentum (i.e., high-k) photonic modes could enable many applications such as imaging, focusing, and waveguiding in a planar platform at deep-subwavelength scales. However, its practical implementation in experiments remains elusive so far. Here we propose a class of hyperbolic metasurfaces, which is characterized by an anisotropic magnetic sheet conductivity and can support the in-plane ultra-high-k magnetic designer polaritons. Based on such metasurfaces, we report the experimental observation of the all-angle negative refraction of designer polaritons at extremely deep-subwavelength scales. Moreover, we directly visualize the designer polaritons with hyperbolic dispersions. Importantly, for these hyperbolic polaritons, we find that their squeezing factor is ultra-large. To be specific, it can be up to 129 in the experiments, an ultra-high value exceeding those in naturally hyperbolic materials. This work may pave a way toward exploring the extremely high confinement and unusual propagation of magnetic designer polaritons over monolayer or twisted bilayer hyperbolic metasurfaces.

Chromatic aberration-free meta-devices (e.g., achromatic meta-devices and abnormal chromatic meta-devices) play an essential role in modern science and technology. However, current efforts suffer the issues of low efficiency, narrow operating band, and limited wavefront manipulation capability. We propose a general strategy to design chromatic aberration-free meta-devices with high-efficiency and ultrabroadband properties, which is realized by satisfying the key criteria of desirable phase dispersion and high reflection amplitudes at the target frequency interval. The phase dispersion is tuned successfully based on a multiresonant Lorentz model, and high reflection is guaranteed by the presence of the metallic ground. As proof of the concept, two microwave meta-devices are designed, fabricated, and experimentally characterized. An achromatic meta-mirror is proposed within 8 to 12 GHz, and another abnormal chromatic meta-mirror can tune the reflection angle as a linear function. Both meta-mirrors exhibit very high efficiencies (85% to 94% in the frequency band). Our findings open a door to realize chromatic aberration-free meta-devices with high efficiency and wideband properties and stimulate the realizations of chromatic aberration-free meta-devices with other functionalities or working at higher frequency.