Ren Zhuang, Xu Jinyi, Liu Jinming, Li Bolin, Zhou Chun, Sheng Zhigao
Anhui Key Laboratory of Condensed Matter Physics at Extreme Conditions, High Magnetic Field Laboratory, HFIPS, Anhui, Chinese Academy of Sciences, Hefei 230031, P. R. China.
University of Science and Technology of China, Hefei 230026, P. R. China.
ACS Appl Mater Interfaces. 2022 Jun 2. doi: 10.1021/acsami.2c04736.
Modulating terahertz (THz) waves actively and smartly through an external field is highly desired in the development of THz spectroscopic devices. Here, we demonstrate an active and smart electro-optic THz modulator based on a strongly correlated electron oxide vanadium dioxide (VO). With milliampere current excitation on the VO thin film, the transmission, reflection, absorption, and phase of THz waves can be modulated efficiently. In particular, the antireflection condition can be actively achieved and the modulation depth reaches 99.9%, accompanied by a 180° phase switching. Repeated and current scanning experiments confirm the high stability and multibit modulation of this electro-optic modulation. Most strikingly, by utilizing a feedback loop of "THz-electro-THz" geometry, a smart electro-optic THz control is realized. For instance, the antireflection condition can be stabilized precisely no matter what the initial condition is and how the external environment changes. The proposed electro-optic THz modulation method, taking advantage of strongly correlated electron material, opens up avenues for the realization of THz smart devices.
在太赫兹光谱设备的发展中，非常需要通过外部场来主动且智能地调制太赫兹（THz）波。在此，我们展示了一种基于强关联电子氧化物二氧化钒（VO₂）的主动且智能的电光太赫兹调制器。在VO₂薄膜上施加毫安级电流激发时，太赫兹波的透射、反射、吸收和相位都能被有效调制。特别地，可以主动实现抗反射条件，调制深度达到99.9%，同时伴随着180°的相位切换。重复和电流扫描实验证实了这种电光调制的高稳定性和多位调制。最引人注目的是，通过利用“太赫兹 - 电 - 太赫兹”几何结构的反馈回路，实现了智能电光太赫兹控制。例如，无论初始条件如何以及外部环境如何变化，抗反射条件都能被精确稳定。所提出的电光太赫兹调制方法，利用强关联电子材料，为实现太赫兹智能设备开辟了道路。
