Investigation of Science and Technology of THz Air Plasma

目的在天文学、全球环境监测和国土安全等领域，远距离、宽带太赫兹波传感技术的发展滞后于迫切的需求。这是由于环境湿度在太赫兹范围内的高吸收率所带来的挑战。本提案的目的是研究太赫兹空气等离子体技术，以应对这一巨大挑战。智能优点环境空气，当被强烈的飞秒激光激发时，通过光学非线性过程显示出非凡的能力来产生和探测脉冲太赫兹波。使用空气等离子体作为宽带太赫兹波发射器和太赫兹波传感器，可提供卓越的频率带宽(0.1-40太赫兹)、峰值场强(1 MV/厘米)、灵敏度(外差)和分辨率(MHz)。我们建议衡量？整改？利用光学斯塔克效应对等离子体灯丝内部太赫兹场与双色激光光束的极限进行了探讨。更广泛的影响对太赫兹成像的最大需求是无损评估系统的形式。国防和国土安全领域的供应商正在寻找更好地感知生化武器和爆炸物的方法。我们拟议的太赫兹空气等离子体项目的开发将提供关键技术，使跨学科研究成为可能，并推动众多太赫兹波传感和成像技术的发展。作为跨学科研究，这一更新项目将继续提供极好的合作机会，在不同种族背景的学生和代表性不足的群体中促进教学、培训和学习。

Objective The development of remote, broadband THz wave sensing technology is lagging behind the compelling needs that exist in the areas of astronomy, global environmental monitoring, and homeland security. This is due to the challenge posed by high absorption by ambient moisture in the THz range. The objective of this proposal is to investigate THz air-plasma technology to meet this great challenge. 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-plasma as a broadband THz wave emitter and THz wave sensor provides superior frequency bandwidth (0.1 - 40 THz), peak field strength ( 1MV/cm), sensitivity (heterodyne), and resolution ( MHz). We propose to measure the ?rectified? THz field inside of the plasma filament with two-color laser beams by using the optical Stark effect to explore the limitation. Broader impact The greatest demand for THz imaging is in the form of a nondestructive evaluation system. Suppliers within the fields of defense and homeland security are seeking ways to better sense chemical and biological weapons and explosives. Our proposed development of the THz air-plasma project will provide key technology that will enable interdisciplinary research and advance numerous THz wave sensing and imaging developments. As interdisciplinary research, this renewal project will continue to provide excellent collaborative opportunities to promote teaching, training, and learning among students with diverse ethnic backgrounds and within underrepresented groups.