MRI: Development of THz Wave Air-Plasma Photonics

摘要太赫兹空气等离子体光子学仪器的发展对激光诱导空气等离子体强宽带太赫兹波的产生和探测、太赫兹遥感和非线性太赫兹光谱学的深入研究至关重要。我们提出的仪器将通过探索极端条件下（电场强度）太赫兹产生和探测的物理机制来解锁研究，具有无与伦比的频率带宽、灵敏度和远程探测能力。气体中的聚焦光脉冲（mJ脉冲能量和30飞秒脉冲持续时间）会产生等离子体，在远场产生太赫兹波。使用空气击穿相干探测（ABCD）或太赫兹增强荧光（TEF）方法，该等离子体也可以探测脉冲太赫兹波，具有潜在的距离传感能力。知识价值：环境空气，当被强烈的飞秒激光束激发时，表现出通过光学非线性过程产生和探测脉冲太赫兹波的非凡能力。使用空气（或选定的气体）作为宽带太赫兹波发射器和太赫兹波传感器提供了优越的带宽（0.1 - 30太赫兹），灵敏度（外差），分辨率（MHz），以及在大气中由于水蒸气衰减而被认为不可能实现的距离传感能力。更广泛的影响：我们提出的太赫兹空气等离子体光子学系统将提供一个关键的仪器，将使跨学科研究和推进许多太赫兹波传感和成像的发展。该仪器将成为太赫兹中心11位教职员工、50多名学生和高级研究人员的主要共享仪器之一，并将提供给来自全球各地的国内和国际合作者。

AbstractThe development of terahertz wave air-plasma photonics instrumentation is crucial for the advanced research of intense broadband THz wave generation and detection in laser-induced air-plasma, remote THz sensing, and nonlinear THz spectroscopy. Our proposed instrument will unlock research by exploring the physical mechanisms for THz generation and detection under extreme conditions (E-field strength) with unparalleled breadth of frequency bandwidth, sensitivity, and remote detection capability. A focused optical pulse (mJ pulse energy and 30 femtosecond pulse duration) in gas creates a plasma, which produces THz waves in the far field. Using either air-breakdown-coherent-detection (ABCD) or THz-enhanced-fluorescence (TEF) methods, this plasma can also detect pulsed THz waves with potential standoff sensing capability. Intellectual merit: Ambient air, when excited with intense femtosecond laser beams, exhibits a remarkable ability to generate and detect pulsed THz waves through an optical nonlinear process. The use of air (or selected gases) as a broadband THz wave emitter and THz wave sensor provides superior bandwidth (0.1 - 30 THz), sensitivity (heterodyne), resolution (MHz), and the standoff sensing capability in atmosphere which was heretofore considered impossible due to water vapor attenuation. Broader impact: Our proposed THz air-plasma photonics system will provide a key instrument that will enable interdisciplinary research and advance numerous THz wave sensing and imaging developments. This instrument will be one of the major shared instruments in the THz Center for eleven faculty members, and over 50 students and senior researchers, and will be made available to our national and international collaborators from around the globe.