飞秒激光的等离子体吸收太赫兹特性研究

在利用飞秒激光器产生太赫兹波的过程中，等离子体本身会对太赫兹波能量进行吸收，其吸收特性在太赫兹波雷达探测、等离子体隐身、电磁干扰研究等方面有着广泛的应用前景。结合理论分析设计了一种等离子体吸收太赫兹波的测量系统，提出等离子体粒子间相互碰撞吸收是导致等离子体吸收太赫兹波的主要原因，并在实验测量研究中发现等离子体密度大小、光学透镜焦距长短以及入射飞秒激光与倍频晶体晶轴角度是影响吸收程度的主要因素，这些研究为等离子体吸收应用提供了更加全面的理论支撑，有助于推动太赫兹波技术在军事及民用领域的快速发展。

Study on characteristic of terahertz absorption of femtosecond laser plasma

In the process of generating terahertz (THz) waves using femtosecond lasers, the plasma absorbs the THz wave energy, and the absorption characteristics have a great application prospects in the THz wave radar detection, plasma stealth, electromagnetic interference research. A measurement system of THz absorption via plasma was designed combining the theoretical analysis, and it was proposed that the interaction between plasma particles was the main reason for the plasma absorption of terahertz waves. The results show that the plasma density, the focal length of the optical lens and the angle of the incident femtosecond laser and the multiplier crystal are the main factors that affect the absorption degree, which provides a more comprehensive theoretical support for the plasma absorption application, it will be helpful to promote the THz wave technology in the military and civilian areas with rapid development.