Ultra-high THz-field-confinement at LaAlO3 twin walls
TUD Dresden University of Technology（德累斯顿工业大学）；University of Geneva（日内瓦大学）；Helmholtz-Zentrum Dresden Rossendorf（德累斯顿-罗斯多夫亥姆霍兹中心）；Lawrence Berkeley National Laboratory（劳伦斯伯克利国家实验室）
Jakob Wetzel, Javier Taboada-Gutiérrez, Matthias Roeper, Felix G. Kaps, Giuliano Esposito, Drini Marchese, Robin Buschbeck, Pauline Lenz, J. Michael Klopf, Hans… 展开作者
Jakob Wetzel, Javier Taboada-Gutiérrez, Matthias Roeper, Felix G. Kaps, Giuliano Esposito, Drini Marchese, Robin Buschbeck, Pauline Lenz, J. Michael Klopf, Hans A. Bechtel, Stephanie N. Gilbert Corder, Jeremie Teyssier, Susanne C. Kehr, Lukas M. Eng, Alexey B. Kuzmenko, Samuel D. Seddon
The control and steering of light at nanometre length scales is crucial for the development of both fundamental science and nanophotonic technologies. Recent advancements have been achieved by exploiting various crystalline anisotropies, allowing for subdiffractional and diffraction-less canalisation of energy. These studies in particular benefit from stacking and twisting of 2D materials, whereas corresponding capabilities of anisotropic bulk crystals are rather unexplored. In this work, we show that ferroelastic twin walls - crystallographically perfect 2D-sheets that separate regions of differently oriented domains - in the distorted perovskite LaAlO3 provide a natural platform for broadband lateral confinement and superb canalisation of light at the nanoscale. Without fabrication processes, the electromagnetic fields localised at such walls exhibit lateral optical sizes up to 260 times smaller than the free-space wavelength. Depending on the adjacent domain orientation and frequency, the twin wall pattern preferentially concentrates or repels the electromagnetic energy, constituting a natural building block towards broadband MIR and THz nanophotonics for polaritonic circuitry.
Near-field perturbation of laser filament enabling simultaneous far-field THz diagnosis and broadband calculus processing
Terahertz Technology Innovation Research Institute, Terahertz Spectrum and Imaging Technology Cooperative Innovation Center, Shanghai Key Lab of Modern Optical System, University of Shanghai for Science and Technology（上海理工大学太赫兹技术创新研究院、太赫兹谱与成像技术协同创新中心、现代光学系统上海市重点实验室）；Shanghai Institute of Intelligent Science and Technology, Tongji University（同济大学上海智能科学与技术研究院）；Tera Aurora Electro-optics Technology Co., Ltd（上海泰奥光电科技有限公司）；Faculty of Physics and International Laser Center, Lomonosov Moscow State University（莫斯科国立大学物理系及国际激光中心）
Ultrasensitive THz sensing with high-Q Fano resonances in metasurfaces
高品质因数共振对于设计超灵敏折射率无标记传感器是非常有希望的，因为它允许电磁波和分析物材料之间的强烈相互作用。超材料和等离子体传感由于其谐振结构中电磁场的亚波长限制而引起了人们的广泛关注。然而，在这些系统中激发高品质因数共振一直是一个挑战。我们激发了一个数量级更高的品质因数共振平面太赫兹超材料，我们利用超灵敏传感。具有极窄线宽的低损耗四极和Fano共振使我们能够测量由于周围介质折射率的最小变化而引起的微小光谱偏移。我们用四极子实现了7.75 x 10^3 nm/ RIU的灵敏度水平，用Fano共振实现了5.7 x 10^4 nm/ RIU的灵敏度水平，这可以通过使用更薄的衬底进一步增强。这些发现将有助于设计超灵敏的实时化学和生物分子传感器的指纹区域的太赫兹制度。
