太赫兹超表面中的连续域束缚态

Bound States in Continuum in Terahertz Metasurface

连续域束缚态(BIC)是发生在辐射连续域频率范围内且被完全局域的共振,具有无限大的Q值,光与物质之间产生强相互作用,该现象对新型功能器件的发展至关重要。在太赫兹超表面中引入BIC机制,为定制高Q值共振提供了新的思路。从BIC的分类、形成机制、基本性质等方面对BIC进行了简要描述,重点介绍了BIC在THz超表面中的新应用,如高灵敏度传感、手性增强、光谱编码、近场成像。此外,BIC携带拓扑电荷,由偏振矢量缠绕圈数定义,这样的电荷只能通过改变系统参数来产生或湮灭。BIC的拓扑性质也为拓扑光子学新现象的发现提供了新的可能,BIC现象的研究可以为光学和光子学领域带来更多的发展。

Bound states in the continuum(BIC)is a completely bound resonance with its frequency within the continuum spectrum.It has an infinite Q factor,and strong light-matter interaction.The BIC phenomenon is critical for developing functional devices.The introduction of BIC mechanism in terahertz metasurface provides a new way to customize high Q resonance.In this review,the classification,formation mechanism,and main properties of BIC are briefly introduced,and the emerging applications of BIC in terahertz metasurfaces,such as high sensitivity sensing,chiral enhancement,spectral coding,and near-field imaging,are emphasized.In addition,BIC carries topological charges that are defined by the winding number of the polarization vector,such charges can only be created or annihilated by drastically changing the system parameters.The topological properties of BIC also provide new possibilities for the discovery of new phenomena in topological photonics.In the future,BIC can bring more developments in the field of optics and photonics.