We propose a graphene embedded one-dimensional (1D) topological photonic crystal heterostructure, where the coupling occurs between the topological edge mode (TEM) and the Fabry–Perot cavity mode (CM). It is shown that the coupling leads to the hybridization between TEM and CM, with a Rabi splitting. Based on finite element method, a dual-band near-perfect absorption is found in the Rabi splitting region in near-infrared range. The resonant wavelengths of the two absorption peaks are 1537 and 1579 nm, respectively. And the two absorption peaks can be modulated by the thickness of the defect layer, the coupling distance between TEM and CM, Fermi energy of graphene, and incident angle of light (under TE and TM polarization). In particular, when the Fermi energy of graphene slightly increases over 0.4 eV, the imaginary part of permittivity of graphene is near 0, so does the dual-band absorption. Theoretically, the TEM-CM coupling can be analyzed by the classic oscillator model. The controllable two absorption bands may achieve potential applications in active optoelectronic devices at communication wavelengths, such as optical switches, sensors and modulators.

我们提出了一种石墨烯嵌入的一维 (1D) 拓扑光子晶体异质结构，其中耦合发生在拓扑边缘模式 (TEM) 和法布里-珀罗腔模式 (CM) 之间。结果表明，耦合导致 TEM 和 CM 之间的杂交，具有 Rabi 分裂。基于有限元方法，在近红外范围的Rabi分裂区发现了双波段近乎完美的吸收。两个吸收峰的共振波长分别为 1537 和 1579 nm。并且这两个吸收峰可以通过缺陷层的厚度、TEM和CM之间的耦合距离、石墨烯的费米能量以及光的入射角（在TE和TM偏振下）来调制。特别是，当石墨烯的费米能量略微增加超过 0.4 eV 时，石墨烯介电常数的虚部接近0，双带吸收也是如此。理论上，TEM-CM 耦合可以通过经典振荡器模型进行分析。可控的两个吸收带可以在通信波长的有源光电器件中实现潜在的应用，例如光开关、传感器和调制器。