谐振器中的损耗问题是现代等离子体和光子元器件的设计和使用中的关键问题。我们提出了一种光谱方法，用于确定材料和辐射损失的结构中的束缚态的连续使用作为例子的相变硫属化物Ge 2Sb 2 Te 5。实验测量了Ge 2Sb 2 Te 5非晶相和晶相的复折射率，并计算了1500 nm通信波长下的共振光学性质。为了证明该方法的有效性，两种类型的谐振器被认为是一个圆柱和一个环，支持束缚态的连续根据弗里德里希-温特根机制。我们测定了非晶态Ge_2Sb_2 Te_5的材料质量因子为Qmat = 46，在连续谱束缚态范围内，一对TE_（0，1，2）和TE_（0，2，0）模的圆柱辐射质量因子为Qrad = 608，环辐射质量因子为Qrad = 332。我们还证明了两种机制的非晶相和晶相之间的散射光谱的有效切换的Ge 2Sb 2 Te 5。
英文摘要：
The problem of losses in resonators is a key issue in the design and use of modern plasmonic and photonic meta-devices. We propose a spectroscopic method for determining material and radiation losses in structures with bound states in the continuum using as example the phase-change chalcogenide Ge2Sb2Te5. The complex refractive index for the amorphous and crystalline Ge2Sb2Te5 phases was measured experimentally, and the resonance optical properties were calculated for a telecommunication wavelength of 1500 nm. To demonstrate the validity of the method, two types of resonators were considered - a cylinder and a ring which support bound states in the continuum according to the Friedrich - Wintgen mechanism. We have determined the value of the material quality-factor for the amorphous Ge2Sb2Te5 as Qmat = 46 and the values of the radiation quality-factors Qrad = 608 for the cylinder and Qrad = 332 for the ring of a pair of TE0,1,2 and TE0,2,0 modes in the regime of bound states in the continuum. We also demonstrated two mechanisms for efficient switching of the scattering spectra between the amorphous and crystalline phases of Ge2Sb2Te5.
Size Scaling Law for Radiation Losses of Modes in Photonic Crystal Surface Emitting Devices
College of Advanced Interdisciplinary Studies, National University of Defense Technology（国防科技大学前沿交叉学院）；Nanhu Laser Laboratory, National University of Defense Technology（国防科技大学南湖激光实验室）；Hunan Provincial Key Laboratory of High Energy Laser Technology, National University of Defense Technology（国防科技大学高能激光技术湖南省重点实验室）；Qingdao Innovation and Development Center, Harbin Engineering University（哈尔滨工程大学青岛创新发展基地）
Topological nature of bound states in the radiation continuum
连续介质中的束缚态（英语：Bound states in the continuum，BIC）是描述光或物质的波动方程的不寻常解：它们是离散的，空间上有界的，但与传播到无穷远的连续介质的能量相同。直到最近，BIC都是通过微调波动方程中的参数或利用波动方程由于对称性而具有的可分性来构造的。最近，已经预测并实验性地在周期性结构中实现了既鲁棒又不受保护（意外）的BIC;最简单的这种系统是周期性电介质板，其也具有受保护的BIC。在这里，我们表明，这两种类型的BIC在这样的系统中的涡流中心的偏振方向的远场辐射。这些BIC的鲁棒性是由于存在守恒和量子化的拓扑电荷，定义的偏振矢量的次数围绕涡旋中心。这种电荷只能通过系统参数的大变化产生或湮灭，然后只能根据严格的规则，我们推导和测试数值。我们的结果意味着基于这种状态的激光发射将产生矢量光束。
Robustness of Bound States in the Continuum in Bilayer Structures against Symmetry Breaking
Qingdao Innovation and Development Center of Harbin Engineering University（哈尔滨工程大学青岛创新发展基地）；School of Physics and Engineering, ITMO University（ITMO大学物理与工程学院）；Ioffe Institute（约费研究所）
Substrate-engineered tunable bound states in the continuum and directional radiation in dielectric metasurfaces
Neijiang Normal University（内江师范学院）；Neijiang Optoelectronic Devices Engineering Research Center（内江光电器件工程研究中心）；Shenzhen University（深圳大学）；Great Bay University（大湾区大学）；Chongqing University（重庆大学）
Engineering Nanophotonic Modes via the Radiation Continuum
Laboratoire de Physique et d’Étude des Matériaux, LPEM, UMR 8213, ESPCI Paris, Université PSL, CNRS, Sorbonne Université（材料物理与表征实验室）；DOTA, ONERA, Université Paris-Saclay（ONERA巴黎萨克雷大学）；Centre de Nanosciences et de Nanotechnologies, CNRS – Université Paris-Sud-Paris-Saclay（纳米科学和纳米技术研究中心）
