PFI:AIR-TT: Continuous-wave room-temperature terahertz quantum cascade laser sources

该PFI：AIR技术转化项目的重点是转化半导体量子级联激光器技术，以满足对紧凑、廉价、可广泛调谐的室温太赫兹辐射源的需求。太赫兹量子级联激光器有望成为第一个频率捷变连续波室温太赫兹源，具有二极管激光器的成本，大规模生产潜力，尺寸和操作简单性。预计将受益于该源技术的商业应用包括：工业环境中涂层（湿漆和干漆、塑料、纸张、片剂涂层）的实时非接触式厚度测量、气体传感、THz成像、光谱学和显微镜。这项新技术预计将大幅降低现有太赫兹系统的成本和尺寸。该项目解决了连续波室温太赫兹量子级联激光源从研究发现转向商业应用过程中增加功率输出和简化处理的需求。这将通过使用高质量的材料生长、热封装以及器件有源区和波导设计的创新来实现。这些创新有望将功率输出从目前的14微瓦提高到50微瓦以上，并简化设备处理。 此外，参与该项目的人员，两名电气工程专业的研究生和一名技术商业化专业的科学硕士，将获得将复杂半导体器件技术推向应用的独特经验。该项目专注于1- 2000年频率捷变窄线宽连续波源的开发和营销。6 THz光谱范围，超过50微瓦功率输出，这足以满足大多数太赫兹应用。频率捷变连续波THz源对于THz应用是高度期望的，因为（a）它们的窄带发射频率可以被选择为落在大气水吸收线之间，（B）它们可以用作外差THz检测器、高分辨率光谱学和气体感测的本地振荡器源，以及（c）它们的辐射可以使用基于高灵敏度室温肖特基二极管的检测器来检测。预计将受益于我们源技术的商业应用包括：工业环境中涂层的实时非接触式厚度测量这些设备包括：光学仪器（湿漆和干漆、塑料、纸张、片剂涂层）、气体传感、太赫兹成像以及用于材料表征的各种科学仪器，如近场和远场太赫兹显微镜、高分辨率光谱仪和射电天文学的本地振荡器源。中红外量子级联激光器的基本器件技术是腔内差频产生。为了实现高功率连续波操作目标，该团队将联合收割机结合他们在高功率连续波中红外量子级联激光器的生长和热封装方面的专业知识，并将进一步在器件有源区和波导中实施创新，预计将室温连续波功率输出从目前的14微瓦提高到50微瓦以上，并简化器件加工。

This PFI: AIR Technology Translation project focuses on translating the technology of semiconductor quantum cascade lasers to fill the need of compact and inexpensive widely-tunable room-temperature sources of terahertz radiation. Terahertz quantum cascade lasers are expected to become the first frequency-agile continuous-wave room-temperature terahertz sources with the cost, mass-producibility potential, size, and operation simplicity of diode lasers. Commercial applications that are expected to benefit from this source technology include: real-time non-contact thickness measurements of coatings in industrial environments (wet and dry paints, plastics, paper, tablet coatings), gas sensing, THz imaging, spectroscopy, and microscopy. The new technology is expected to dramatically reduce the cost and size of existing terahertz systems.This project addresses the need to increase the power output and simplify processing of continuous-wave room-temperature terahertz quantum cascade laser sources as they translate from research discovery toward commercial application. This will be achieved by using high-quality materials growth, thermal packaging, and innovations in the device active region and waveguide designs. These innovations are expected to boost the power output from the current record of 14 microwatt to over 50 microwatt and simplify device processing. In addition, personnel involved in this project, two graduate students in the Electrical Engineering program and one student in the Master's of Science in Technology Commercialization program, will receive a unique experience of advancing a complex semiconductor device technology to applications.The project focuses on the development and marketing of frequency-agile narrow-linewidth continuous-wave sources in 1-6 THz spectral range with over 50 microwatt power output, which is sufficient for most terahertz applications. Frequency-agile continuous-wave THz sources are highly desired for THz applications because (a) their narrowband emission frequencies can be selected to fall between atmospheric water absorption lines, (b) they can be used as local oscillator sources for heterodyne THz detectors, high-resolution spectroscopy, and gas sensing, and (c) their radiation can be detected using highly-sensitive room-temperature Schottky-diode based detectors. Commercial applications that are expected to benefit from our source technology include: real-time non-contact thickness measurements of coatings in industrial environments (wet and dry paints, plastics, paper, tablet coatings), gas sensing, THz imaging, and a variety of scientific instruments for materials characterization, such as near-field and far-field THz microscopes, high-resolution spectrometers, and local oscillator sources for radio-astronomy. The basic device technology is intracavity difference-frequency generation in mid-infrared quantum cascade lasers. To achieve high-power continuous-wave operation goal the team will combine their expertise in growth and thermal packaging of high-power continuous-wave mid-infrared quantum cascade lasers and will further implement innovations in the device active region and waveguide that are expected to boost room-temperature continuous-wave power output from the current record of 14 microwatts to over 50 microwatts and simplify device processing.