近日，上海交通大学盛政明团队研究了激光诱导空气细丝太赫兹辐射的偏振和振幅调谐。相关论文于2025年4月15日发表在《物理评论A》杂志上。

具有可调谐偏振和振幅的太赫兹辐射可以促进在许多领域的应用，如生物诊断和太赫兹成像。

研究组利用光电流模型和远场相干叠加方法，研究了双色激光诱导空气丝在采用圆极化基波和椭圆极化次谐波的情况下，产生的太赫兹辐射的偏振和幅值独立控制。通过调节双色组分的初始相对相位和灯丝长度，可以独立控制太赫兹辐射的偏振，包括偏振角和偏振椭圆率。

同时，通过将二次谐波的偏振椭圆率从1（偏振方向与基波相反）增加到1，可以使太赫兹辐射的振幅从0连续调谐到最大值，并使其偏振固定在理想状态。该研究为操纵太赫兹辐射的多个参数提供了一种全光学方法，这是太赫兹科学的主题。

附：英文原文

Title: Polarization and amplitude tuning of terahertz radiation from laser-induced air filaments

Author: Hanzhi Zhang, Linzheng Wang, Yanping Chen, Zhelin Zhang, Zhengming Sheng

Issue&Volume: 2025/04/15

Abstract: Terahertz radiation with tunable polarization and amplitude can facilitate applications in many fields such as biological diagnosis and terahertz imaging. Using the photocurrent model and far-field coherent superposition method, we show that two-color laser-induced air filaments can generate terahertz radiation with independent control on both its polarization and amplitude when a circularly polarized fundamental wave and an elliptically polarized second harmonic are adopted. The polarization of the terahertz radiation, including polarization angle and polarization ellipticity, can be controlled independently by tuning the initial relative phase between two-color components and the filament length, respectively. Meanwhile, by increasing the polarization ellipticity of the second harmonic from 1 (with polarization opposite to the fundamental wave) to 1, the amplitude of the terahertz radiation can be tuned continuously from 0 to its maximum with its polarization fixed at a desirable state. Our studies provide an all-optical method for the manipulation of multiple parameters of terahertz radiation, which is useful for terahertz science.

DOI: 10.1103/PhysRevA.111.043516

Source: https://journals.aps.org/pra/abstract/10.1103/PhysRevA.111.043516