Yu Anqi, Yang Zhenyu, Cai Miao, Zhang Huiping, Tian Zhengan, Guo Xuguang, Wang Lanxia, Balakin Alexei V, Shkurinov Alexander P, Zhu YiMing
Shanghai Key Lab of Modern Optical System, Terahertz Technology Innovation Research Institute, Terahertz Spectrum and Imaging Technology Cooperative Innovation Center, University of Shanghai for Science and Technology, 516 Jungong Road, Shanghai 200093, China.
Shanghai Institute of Intelligent Science and Technology, Tongji University, Shanghai 200092, China.
Nanophotonics. 2022 Nov 4;11(21):4737-4745. doi: 10.1515/nanoph-2022-0455. eCollection 2022 Dec.
Terahertz detectors based on two-dimensional Dirac materials offer a new approach for room-temperature terahertz detection with high response and low noise. However, these devices can hardly show high response over a broad frequency range, mainly due to the poor absorption caused by their ultrathin nature. Here we apply metallic gratings to enhance the excitation efficiency of graphene plasmons. When nonzero source-drain bias is applied, graphene plasmons can generate terahertz response orthogonal to the polarization of the incidence. The response is attributed to the orthogonal overdamped plasmon rectification effect, and graphene plasmons-enhanced photo-thermoelectric effect. By comparing the normalized on/off ratio, the metallic gratings are found to effectively enhance the coupling efficiency between graphene plasmons and THz incidence, and thus the absorption and responsivity. The results are beneficial for improving the response of room temperature THz detectors.
基于二维狄拉克材料的太赫兹探测器为室温下的高响应、低噪声太赫兹探测提供了一种新方法。然而，这些器件很难在较宽的频率范围内表现出高响应，这主要是由于其超薄特性导致的吸收较差。在此，我们应用金属光栅来提高石墨烯等离子体激元的激发效率。当施加非零源漏偏压时，石墨烯等离子体激元可以产生与入射偏振正交的太赫兹响应。该响应归因于正交过阻尼等离子体激元整流效应以及石墨烯等离子体激元增强的光热电效应。通过比较归一化的开/关比，发现金属光栅有效地提高了石墨烯等离子体激元和太赫兹入射之间的耦合效率，从而提高了吸收率和响应度。这些结果有利于改善室温太赫兹探测器的响应。
