Wang Hongqiang, Mao Yu, Kislyakov Ivan M, Dong Ningning, Chen Chenduan, Wang Jun
Opt Lett. 2021 Apr 15;46(8):1812-1815. doi: 10.1364/OL.419976.
Tellurium (Te) is a novel elementary material, which has recently attracted extensive attention due to its intriguing physical properties, such as topological, thermoelectric, and photoelectric properties. Further study on Te crystal structures will help to understand its properties and facilitate its application. Here, the angle-resolved polarized Raman spectroscopy has been employed to study Te crystal symmetry. Three different Raman vibration modes were obtained, each of which possess a different polarization dependence. Furthermore, it is revealed that Te nanosheets show a second-order harmonic response over a wide spectrum and have the greatest conversion efficiency at an excitation wavelength of 880 nm. Its second-order nonlinear susceptibility is estimated to be 2049. This substantial nonlinear optical response endows Te nanosheets with the potential for developing nonlinear photonic and optoelectronic nanodevices with high efficiency.
碲（Te）是一种新型单质材料，由于其具有如拓扑、热电和光电等有趣的物理特性，最近受到了广泛关注。对碲晶体结构的进一步研究将有助于理解其性质并促进其应用。在此，采用角分辨偏振拉曼光谱法研究碲晶体对称性。获得了三种不同的拉曼振动模式，每种模式都具有不同的偏振依赖性。此外，研究表明碲纳米片在宽光谱范围内表现出二阶谐波响应，并且在880 nm的激发波长下具有最大的转换效率。其二阶非线性极化率估计为2049。这种显著的非线性光学响应使碲纳米片具有开发高效非线性光子和光电子纳米器件的潜力。
