Opt Lett. 2023 Mar 1;48(5):1256-1259. doi: 10.1364/OL.483817.
In this Letter, an ultracompact terahertz (THz) mode division multiplexer based on THz spoof surface plasmon polaritons (SPPs) is proposed. Compared with traditional optical multiplexing devices, the proposed mode multiplexer can be designed with a reduced footprint by exploiting more degrees of freedom in the parameters of the unit cell, namely a rectangular metallic pillar. The ultracompact mode division multiplexer can simultaneously support the propagation of four mode channels: the TM, TM, TM, and TM modes. Then, we numerically evaluate the performance of a cascaded plasmonic mode division circuit composed of a mode multiplexer and demultiplexer. The cross talk and excess loss of the whole circuit are lower than -15 dB and 3.7 dB, respectively, for all four mode channels at a center frequency of 0.65 THz. The footprint of the whole device is about 27 × 2.3 mm and the length of each coupling region is about 2.7 mm. For the first time, to the best of our knowledge, a mode division multiplexer based on THz spoof SPPs is reported, which will form core devices for future THz on-chip multimode communication systems.
在这篇快报中，提出了一种基于太赫兹（THz）赝表面等离激元（SPPs）的超紧凑太赫兹模式分复用器。与传统的光学复用器件相比，所提出的模式复用器可以通过利用单元的参数（即矩形金属柱）中的更多自由度来设计具有更小的占用面积。超紧凑模式分复用器可以同时支持四个模式通道的传播：TM、TM、TM 和 TM 模式。然后，我们数值评估了由模式复用器和解复用器组成的级联等离子体模式分路电路的性能。在中心频率为 0.65 THz 时，整个电路的串扰和过剩损耗对于所有四个模式通道均低于-15 dB 和 3.7 dB。整个器件的占用面积约为 27×2.3mm，每个耦合区域的长度约为 2.7mm。据我们所知，这是首次报道基于太赫兹赝 SPP 的模式分复用器，它将成为未来太赫兹片上多模通信系统的核心器件。
