Wang Wen-Ya, Ren Hang, Xu Zhao-Hua, Chen Hong, Li Yuanzhen, Xu Su
Opt Lett. 2024 Oct 1;49(19):5579-5582. doi: 10.1364/OL.535079.
Integrated power dividers (PDs) are essential in terahertz (THz) communication and radar systems, but miniaturization often leads to performance degradation due to fabrication inaccuracies and sharp bends. Topological photonics offers a solution to these issues, yet creating THz power dividers with arbitrary splitting ratios remains challenging. We present a design methodology for on-chip topological THz power dividers with customizable splitting ratios using valley-locked photonic crystals. These crystals feature a tri-layered structure with two distinct valley Chern number layers and an intermediate semimetal layer. Utilizing the Jackiw-Rebbi model, we show that the characteristic impedance of the valley-locked photonic crystals, and thus the power division ratio, can be tuned by adjusting the semimetal layer width. Our approach is validated through simulations and experiments for both equal (1:1) and unequal (4:9) power ratios. This method enables efficient navigation around sharp bends and robust THz on-chip connectivity.
集成功率分配器（PD）在太赫兹（THz）通信和雷达系统中至关重要，但由于制造误差和急剧弯曲，小型化往往会导致性能下降。拓扑光子学为这些问题提供了一种解决方案，然而，制造具有任意功率分配比的太赫兹功率分配器仍然具有挑战性。我们提出了一种使用谷锁定光子晶体设计具有可定制功率分配比的片上拓扑太赫兹功率分配器的方法。这些晶体具有三层结构，包括两个不同的谷陈数层和一个中间半金属层。利用Jackiw-Rebbi模型，我们表明，通过调整半金属层宽度，可以调节谷锁定光子晶体的特性阻抗，从而调节功率分配比。我们的方法通过对相等（1:1）和不相等（4:9）功率比的模拟和实验得到了验证。这种方法能够在急剧弯曲处实现高效导航，并实现稳健的太赫兹片上连接。
