各向异性
太赫兹辐射
材料科学
凝聚态物理
格子(音乐)
晶格平面
光学
光电子学
物理
衍射
声学
互易晶格
作者
Jiangpeng Dong,Kevin-P. Gradwohl,Yadong Xu,Tao Wang,Binbin Zhang,Bao Xiao,Christian Teichert,Wanqi Jie
出处
期刊:Photonics Research
[The Optical Society]
日期:2019-04-15
卷期号:7 (5): 518-518
被引量:7
摘要
In this work, a model based on the optical rectification effect and the photocurrent surge effect is proposed to describe the terahertz emission mechanism of the layered GaTe crystal. As a centrosymmetric crystal, the optical rectification effect arises from the breaking of the inversion symmetry due to lattice reorganization of the crystal’s surface layer. In addition, the photocurrent surge originating from the unidirectional charge carrier diffusion—due to the noncubic mobility anisotropy within the layers—produces terahertz radiation. This is confirmed by both terahertz emission spectroscopy and electric property characterization. The current surge perpendicular to the layers also makes an important contribution to the terahertz radiation, which is consistent with its incident angle dependence. Based on our results, we infer that the contribution of optical rectification changes from 90% under normal incidence to 23% under a 40° incidence angle. The results not only demonstrate the terahertz radiation properties of layered GaTe bulk crystals, but also promise the potential application of terahertz emission spectroscopy for characterizing the surface properties of layered materials.
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