论文标题
连续体中的绑定状态和配备金属光栅的电介质波导中的特殊点
Bound states in the continuum and exceptional points in dielectric waveguide equipped with a metal grating
论文作者
论文摘要
连续体（BICS）和特殊点（EPS）的结合状态一直是最近强化研究的主题，因为它们表现出对基本物理和实际应用都很重要的外来现象。我们研究了Friedrich-Wintgen（FW）型BIC和EP在介电波导中的出现，其中包括金属光栅，重点是它们对光栅厚度的依赖。 BIC出现在由两种波导模式形成的抗穿刺附近的分支上，用于任何厚度的光栅。随着光栅厚度的变化，抗跨间隙的变化和BIC出现的分支变化。我们表明，当狭缝是单个模式时，BIC出现在空晶格（零狭缝宽度）限制中的两个波导模式之间的交叉处，而结果满足了BIC在上一个报告中出现的分支的标准。此外，我们发现EP仅在选择光栅厚度时出现在同一设备中的BIC附近。介电波导中的BIC和EP包括金属光栅，尤其是具有这种可调节性，还预计还会导致功能性和高性能光子设备的发展，除了是非赫米蒂亚系统基础研究的平台外。
Bound states in the continuum (BICs) and exceptional points (EPs) have been the subjects of recent intensive research as they exhibit exotic phenomena that are significant for both fundamental physics and practical applications. We investigated the emergence of the Friedrich-Wintgen (FW) type BIC and the EP in a dielectric waveguide comprising a metal grating, focusing on their dependence on the grating thickness. The BIC emerges at a branch near the anti-crossing formed of the two waveguide modes, for a grating of any thickness. With the grating-thickness change, the anti-crossing gap varies and the branch at which the BIC appears flips. We show that, when the slit is single mode, the BIC appears at the crossing between the two waveguide modes in the empty-lattice (zero slit-width) limit, while the results satisfy the criteria for the branch at which the BIC appears in the previous reports. In addition, we find that the EP appears near the BIC in the same device only on selecting the grating thickness. The BIC and EP in the dielectric waveguide comprising a metal grating, particularly with such tunability, are expected to result in the development of functional and high-performance photonic devices in addition to being a platform for the fundamental research of non-Hermitian systems.
