Chen Jianfeng, Liang Wenyao, Li Zhi-Yuan
Opt Lett. 2020 Sep 15;45(18):4964-4967. doi: 10.1364/OL.401650.
We present a scheme to realize topological slow-light state with low group velocity and vanishing group velocity dispersion. By harnessing the strong interactions between two regular co-propagating topological photonic states in a magneto-optical photonic crystal waveguide, the energy flux transport of light exhibits a peculiar eight-shaped flowing loop within each unit cell of the waveguide. This permits the broadband pulse transporting with low group velocity (=13.26), broad bandwidth with a relative bandwidth of 3.08%, large normalized delay-bandwidth product (about 0.409), and vanishing group velocity dispersion. More importantly, they are robust against backscattering from obstacles. Our scheme paves the way to dig into the concept and physics of topology for solving the difficult problems of signal distortion and scattering loss in slow-light systems.
我们提出了一种实现具有低群速度和零群速度色散的拓扑慢光状态的方案。通过利用磁光光子晶体波导中两个同向传播的规则拓扑光子态之间的强相互作用，光的能量通量传输在波导的每个单元胞内呈现出奇特的八字形流动回路。这使得宽带脉冲能够以低群速度（=13.26）传输，具有3.08%的相对带宽的宽带宽、大的归一化延迟带宽积（约0.409）以及零群速度色散。更重要的是，它们对来自障碍物的背向散射具有鲁棒性。我们的方案为深入研究拓扑概念和物理原理以解决慢光系统中的信号失真和散射损耗难题铺平了道路。
