SBIR Phase I: Ultrafast Optoelectronic Devices Based on Field Emission

这个小型企业创新研究第一阶段项目建议确定在共振激光辅助场发射中使用光密化(光学外差)作为产生太赫兹(THz)辐射的新方法的可行性。太赫兹辐射的许多应用包括成像(包装检查、结构检查、癌症检测)、光谱学(催化、反应动力学、环境研究)、天文学(本地振荡器、成像阵列)和高带宽通信。然而，研究人员描述了目前太赫兹源造成的“障碍”，包括有限的带宽和功率。在量子模拟中发现的光辐射与隧穿电子的共振被用来用激光选通场发射电流。由于针尖比激光波长小得多，电子发射在光频上变化，场发射具有高度的非线性，因此可以通过光电混合产生从DC到100 THz的信号。该项目的商业应用将是具有更大带宽的可调信号源。这些设备现在被用作射电天文学的本地振荡器。有一些证据表明，这项新技术在太赫兹频率上可能具有平坦的频率响应。共振激光辅助场发射的可能应用还包括要求场发射对电离辐射和大范围环境温度具有抵抗力的领域。

This Small Business Innovation Research Phase I project proposes to determine the feasibility of using photomixing (optical heterodyning) in resonant laser-assisted field emission as a new means for generating terahertz (THz) radiation. The many applications of THz radiation include imaging (package inspection, structural examination, cancer detection), spectroscopy (catalysis, reaction kinetics, environmental studies), astronomy (local oscillators, imaging arrays), and high-bandwidth communications. However, researchers describe "hurdles" caused by present THz sources, including limited bandwidth and power. A resonance of optical radiation with tunneling electrons, discovered in quantum simulations, was used to gate field emission current with a laser. Because the tip is much smaller than the laser wavelength, electron emission varies at the optical frequency, and field emission is highly nonlinear, so signals from DC to 100 THz could be generated by photomixing. The commercial applications of this project would be tunable sources with greater bandwidth. These devices are now used as local oscillators in radio astronomy.There is some evidence that the new technology may have a flat frequency response at THz frequencies. Possible applications of resonant laser-assisted field emission would also include areas where the resistance of field emission to ionizing radiation and wide ranges of ambient temperature are required.