SBIR Phase I: Compact THz-ABCD Spectrometer

这个小企业创新研究第一阶段的研究项目建议开发一个紧凑的太赫兹（THz）空气击穿相干检测（ABCD）光谱仪。具体而言，本研究将构建和集成这种太赫兹光谱仪的基础上，最近的实验和理论研究产生的宽带太赫兹波在环境空气中的激光诱导等离子体。气体中的聚焦光脉冲产生大气等离子体（电离气体分子），其在远场中产生非常强烈的、高度定向的和超宽带的THz波。通过相互作用，这种等离子体也可以作为一个传感器的脉冲太赫兹波通过空气击穿相干检测。随着二次同步激光脉冲的引入，THz场（振幅、相位和辐射方向）的放大也可以实现，THz科学和技术的最新重大进展将有助于科学家和工程师利用脉冲等离子体发射、控制、增强和测量宽带THz波。应用包括非破坏性测试、断层成像、无标记遗传分析、细胞水平成像、爆炸物检测和化学/生物传感。 除了在太赫兹频率范围内推进众多传感和成像概念外，还将对无损分析产生直接影响，短期应用于国土安全，并对生物医学领域产生长期兴趣。

This Small Business Innovation Research Phase I research project proposes to develop a Compact TeraHertz (THz) Air-Breakdown-Coherent Detection (ABCD) Spectrometer. Specifically, this research will construct and integrate this THz spectrometer based on recent experimental and theoretical research on broadband THz waves produced from laser-induced plasma in ambient air. A focused optical pulse in a gas creates atmospheric plasma (ionized gas molecules) which produces very intense, highly-directional, and ultra-broadband THz waves in the far field. Through the reciprocal process, this plasma could also serve as a sensor of pulsed THz waves through air-breakdown coherent detection. With the introduction of secondary synchronized laser pulses, amplification of the THz field (amplitude, phase, and radiation direction) can also be achieved.Recent significant advances in THz science and technology will help scientists and engineers to use pulsed plasma to emit, control, enhance, and measure broadband THz waves. Applications include non-destructive testing, tomographic imaging, label-free genetic analysis, cellular level imaging, explosives detection, and chemical/biological sensing. In addition to advancing numerous sensing and imaging concepts in the THz frequency range, with an immediate impact on non-destructive analysis, a short-term application for homeland security and a longer-term interest in the biomedical sector.