The nonlinear optical transition bleaching in tellurene
The nonlinear optical transition bleaching in tellurene
复制标题
碲烯中的非线性光学跃迁漂白
作者：
Wang Yiduo;Wang Yingwei;Dong Yulan;Zhou Li;Wei Hao;Long Mengqiu;Xiao Si;He Jun
迄今为止，碲烯的多个二维（2D）相位和光学各向异性引起的突出的线性和非线性光学性质，吸引了潜在的纳米光子学应用的相当大的兴趣。本文通过Z扫描和泵浦探测技术研究了α-碲在宽带光谱区的超快非线性光学（NLO）性质。由于泡利不相容原理，在碲中观察到典型的饱和吸收和带填充效应。利用密度泛函理论（DFT）计算分析表明，在紫外-可见吸收光谱范围内非线性光学响应的增强是由于碲的光学带内跃迁的增加。此外，改变探测脉冲的光子能量的影响进行了探讨。结果表明，较高光子能量的探测脉冲可以产生较小的差分透射信号，这种效应与计算的联合态密度（JDOS）呈负相关。这些结果提供了深入了解2D碲的固有的电子物理学，推动其在光子和光电领域的应用。
To date, outstanding linear and nonlinear optical properties of tellurene, caused by multiple two-dimensional (2D) phases and optical anisotropy, have attracted considerable interest for potential nanophotonics applications. In this work, the ultrafast nonlinear optical (NLO) properties of α-tellurene have been studied via Z-scan and pump–probe techniques at a broadband spectral region. Typical saturable absorption and band filling effects are observed in tellurene due to the Pauli exclusion principle. Analysis using density functional theory (DFT) computation shows the enhancements in NLO response within the ultraviolet–visible absorption spectral region are owing to the increased optical intraband transition in tellurene. Moreover, the effects of varying the photon energy of the probe pulse were explored. Our results indicated that probe pulses with higher photon energies can make smaller differential transmission signal, this effect is found to be negatively correlated with calculated joint density of states (JDOS). These results offer insights into the intrinsic photophysics of 2D tellurene, driving its applications in photonic and optoelectronic fields.