STTR Phase I: Fabrication and Testing of Laser-Assisted Terahertz Field Emitters

这项小型企业技术转移（STTR）第一阶段研究项目将确定开发基于激光辅助场发射的光混合（光学外差）的新型固态器件的可行性，以产生太赫兹（THz）辐射。目前正在研究许多太赫兹应用，包括空气质量监测、癌症检测以及包裹和人员的安全检查。然而，研究人员描述了由于目前太赫兹源造成的“障碍”，包括有限的可调谐带宽和输出功率。光混合现在被用于太赫兹辐射源，PI已经制造了一种新型的微波管，实际上，它为激光辅助场发射的光混合创造了一种纳米级超快非线性光学介质。分析表明，由于场发射的高速和非线性以及分流电容的显著降低，这种新技术可以使太赫兹源具有更大的可调谐带宽和输出功率。建议使用硅纳米技术来开发在大气压下工作的固态器件，因为它们应该比PI早先制造的真空管更容易制造和销售。第一阶段的目标是建立和测试在1太赫兹下输出功率为80 nW的原型，以显示可行性。如果这个项目在开发太赫兹（THz）辐射的新型固态源方面取得成功，那么增加的功率和带宽将有助于许多太赫兹应用，包括科学（天文学、生物学和化学）、医学（癌症检测和牙科成像）和安全技术（检测非金属隐藏武器和爆炸物）。这个项目也可能导致高速计算和通信的进步，在这些领域，现在需要大量的慢得多的设备并行。因此，这将对科学、工业和社会产生深远的影响，从而打开一个强大的市场。这个项目也可能对基础科学有所贡献。光辐射与隧道电子的共振，在模拟中被发现，后来被实验证实，是这项技术的基础。这种共振要求在光场光谱测定金属的局部态密度时进行重大修正，并且它提供了一些关于势垒穿透过程的见解，包括长期争论的量子隧道持续时间的话题。

This Small Business Technology Transfer (STTR) Phase I research project will determine the feasibility of developing new solid-state devices based on photomixing (optical heterodyning) in laser-assisted field emission to generate terahertz (THz) radiation. Many THz applications are now under study, including air quality monitoring, cancer detection, and security screening of packages and personnel. However, researchers describe "hurdles" due to the present THz sources, including limited tunable bandwidth and output power. Photomixing is now used in sources of THz radiation, and the PI has made a new type of microwave tube that, in effect, creates a nanoscale ultrafast non-linear optical medium for photomixing in laser-assisted field emission. Analyses show that this new technique may lead to THz sources having much greater tunable bandwidth and output power because of the high-speed and nonlinearity of field emission and the considerable reduction in the shunting capacitance. It is proposed to use silicon nanotechnology to develop solid-state devices that operate at atmospheric pressure because they should be much easier to manufacture and market than the vacuum tubes which the PI made earlier. The Phase I objective is to build and test prototypes having an output power of 80 nW at 1 THz to show feasibility.If this project is successful in developing new solid-state sources for terahertz (THz) radiation, the increased power and bandwidth could help in many THz applications including science (astronomy, biology, and chemistry), medicine (cancer detection and dental imaging), and security technology (detecting non-metallic concealed weapons and explosives). This project could also lead to progress in high-speed computing and communications where massive paralleling of much slower devices is now required. Thus, there could be a far-reaching impact to benefit science, industry, and society, to open a strong market. This project may also contribute to basic science. A resonance of optical radiation with tunneling electrons, discovered in simulations and later confirmed by experiments, is fundamental to this technology. This resonance requires that a significant correction be made in determining the local density of states in metals by photofield spectroscopy, and it provides some insight in regard to the process of barrier penetration including the long-debated topic of the duration of quantum tunneling.