Özgün Ege, Serebryannikov Andriy E, Ozbay Ekmel, Soukoulis Costas M
NANOTAM-Nanotechnology Research Center, Bilkent University, 06800 Ankara, Turkey.
Faculty of Physics, Adam Mickiewicz University, 61-614 Poznań, Poland.
Sci Rep. 2017 Nov 14;7(1):15504. doi: 10.1038/s41598-017-14982-w.
Combining loss and gain components in one photonic heterostructure opens a new route to efficient manipulation by radiation, transmission, absorption, and scattering of electromagnetic waves. Therefore, loss/gain structures enabling [Formula: see text]-symmetric and [Formula: see text]-broken phases for eigenvalues have extensively been studied in the last decade. In particular, translation from one phase to another, which occurs at the critical point in the two-channel structures with one-dimensional loss/gain components, is often associated with one-way transmission. In this report, broadband mixing of the [Formula: see text]-symmetric and [Formula: see text]-broken phases for eigenvalues is theoretically demonstrated in heterostructures with four channels obtained by combining a one-dimensional loss/gain bilayer and one or two thin polarization-converting components (PCCs). The broadband phase mixing in the four-channel case is expected to yield advanced transmission and absorption regimes. Various configurations are analyzed, which are distinguished in symmetry properties and polarization conversion regime of PCCs. The conditions necessary for phase mixing are discussed. The simplest two-component configurations with broadband mixing are found, as well as the more complex three-component configurations wherein symmetric and broken sets are not yet mixed and appear in the neighbouring frequency ranges. Peculiarities of eigenvalue behaviour are considered for different permittivity ranges of loss/gain medium, i.e., from epsilon-near-zero to high-epsilon regime.
将损耗和增益组件结合在一个光子异质结构中，为通过电磁波的辐射、传输、吸收和散射进行高效操控开辟了一条新途径。因此，在过去十年中，人们对能够实现本征值的[公式：见原文]-对称和[公式：见原文]-破缺相的损耗/增益结构进行了广泛研究。特别是，在具有一维损耗/增益组件的双通道结构中，在临界点处发生的从一个相到另一个相的转变通常与单向传输相关。在本报告中，理论上证明了在通过组合一维损耗/增益双层和一个或两个薄偏振转换组件（PCC）获得的四通道异质结构中，本征值的[公式：见原文]-对称和[公式：见原文]-破缺相的宽带混合。四通道情况下的宽带相混合有望产生先进的传输和吸收模式。分析了各种配置，它们在PCC的对称性质和偏振转换模式方面有所不同。讨论了相混合所需的条件。找到了具有宽带混合的最简单的双组件配置，以及更复杂的三组件配置，其中对称集和破缺集尚未混合，而是出现在相邻的频率范围内。针对损耗/增益介质的不同介电常数范围，即从近零介电常数到高介电常数 regime，考虑了本征值行为的特性。
