Xi Yayan, Zhou Yixuan, Cao Xueqin, Wang Jing, Lei Zhen, Lu Chunhui, Wu Dan, Shi Mingjian, Huang Yuanyuan, Xu Xinlong
Shaanxi Joint Laboratory of Graphene, State Key Laboratory of Photon-Technology in Western China Energy, International Collaborative Center on Photoelectric Technology and Nano Functional Materials, Institute of Photonics & Photon-Technology, School of Physics, Northwest University, Xi'an 710069, China.
Micromachines (Basel). 2023 Jun 12;14(6):1237. doi: 10.3390/mi14061237.
All-optical terahertz (THz) modulators have received tremendous attention due to their significant role in developing future sixth-generation technology and all-optical networks. Herein, the THz modulation performance of the BiTe/Si heterostructure is investigated via THz time-domain spectroscopy under the control of continuous wave lasers at 532 nm and 405 nm. Broadband-sensitive modulation is observed at 532 nm and 405 nm within the experimental frequency range from 0.8 to 2.4 THz. The modulation depth reaches 80% under the 532 nm laser illumination with a maximum power of 250 mW and 96% under 405 nm illumination with a high power of 550 mW. The mechanism of the largely enhanced modulation depth is attributed to the construction of a type-II BiTe/Si heterostructure, which could promote photogenerated electron and hole separation and increase carrier density dramatically. This work proves that a high photon energy laser can also achieve high-efficiency modulation based on the BiTe/Si heterostructure, and the UV-Visible control laser may be more suitable for designing advanced all-optical THz modulators with micro-level sizes.
全光太赫兹（THz）调制器因其在未来第六代技术和全光网络发展中的重要作用而受到了极大关注。在此，通过太赫兹时域光谱技术，在532nm和405nm连续波激光的控制下，研究了BiTe/Si异质结构的太赫兹调制性能。在0.8至2.4THz的实验频率范围内，在532nm和405nm处观察到了宽带敏感调制。在最大功率为250mW的532nm激光照射下，调制深度达到80%；在高功率为550mW的405nm照射下，调制深度达到96%。调制深度大幅增强的机制归因于II型BiTe/Si异质结构的构建，这可以促进光生电子和空穴的分离，并显著提高载流子密度。这项工作证明，高光子能量激光也可以基于BiTe/Si异质结构实现高效调制，并且紫外-可见光控制激光可能更适合设计具有微级尺寸的先进全光太赫兹调制器。
