飞秒激光光丝区域的太赫兹束缚模式研究

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中图分类号：0437 文献标志码：A

Study of terahertz bound modes in femtosecond laser filamentation region

LI Xiaofeng，ZHAO Jiayu （School of Optical-Electrical and Computer Engineering， University of Shanghai for Science and Technology， Shanghai 200093， China）

Abstract： Femtosecond laser pulses can theoretically generate terahertz wave bound modes when focused into filaments. However， due to the extremely high light intensity within the filament， existing detection methods face significant challenges in directly observing these modes. To address thisissue， this paper proposes a novel near-field control and far-field diagnostic method. Specifically， by placing a metal plate parallel to the filament at a sub-terahertz wavelength distance and interacting with the terahertz ring-like mode at the edge of the filament region， the symmetric bound state is transformed into an asymmetric bound state. This mode transition is theoretically manifested as broadband calculus operations of the terahertz time-domain waveform. Experimental results also show that the terahertz time-domain signals in the two mode states indeed exhibit the expected micro-integral relationship， confirming the existence of terahertz bound modes in the filament region. This study provides a new method for observing and controling the interaction between laser filaments and terahertz waves， offering new insights into the coupling effects and spatial bound phenomena between the two.

Keywords： femtosecond laser; plasma filament; terahertz wave; bound state; calculus effect

“飞秒激光成丝辐射太赫兹波”是指飞秒激光在自由空间聚焦后，在焦点附近电离介质（如空气）形成一段等离子体通道（即光丝），并定向辐射太赫兹波的过程。（剩余7769字）