Abstract In this study, the propagation characteristics of electromagnetic waves in a parity-time (PT)-symmetrical 1D photonic crystal comprising dispersed silver layers are investigated. Based on the transmission matrix theory, the total reflection and transmission coefficients of the structure are obtained. It was found that, due to the PT-symmetrical structure, the reflections of the left and right incident waves are nonreciprocal. Numerical simulations indicated that the width of the band gap decreases with the increase in the gain and loss factor ρ in the PT medium, and the band gap ultimately disappears when ρ reaches a critical value, i. e., ρ P T ${\rho }_{PT}$ . With the increase in ρ > ρ P T $\rho { >}{\rho }_{PT}$ , anomalous transmittance and reflection occur within the original bang gap. As the gain and loss factor ρ continue to increase, the abnormal transmittance and reflectivity exhibit a trend of oscillatory decline, and perfect transmission can be achieved at larger values of ρ.

中文翻译：

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准奇偶时间（PT）对称系统中具有金属层的一维光子晶体的电磁传播特性

摘要 在这项研究中，研究了电磁波在包含分散银层的奇偶时间 (PT) 对称一维光子晶体中的传播特性。基于透射矩阵理论，得到了结构的全反射和透射系数。发现由于PT对称结构，左右入射波的反射是非互易的。数值模拟表明，带隙宽度随着 PT 介质中增益和损耗因子 ρ 的增加而减小，当 ρ 达到临界值时，带隙最终消失，即 ρ PT ${\rho }_{ PT}$。随着 ρ > ρ PT $\rho { >}{\rho }_{PT}$ 的增加，原始爆炸间隙内出现异常透射和反射。