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.
