Tunable Continuous Wave THz Source Based on a Room Temperature Quantum Cascade Laser

Northwestern University, Evanston IL

Investigators

Abstract

Objective: The objective of this program is to create a compact, efficient, and tunable continuous wave THz light source at room temperature. This will be accomplished by creating a monolithic, two-frequency, mid-infrared, tunable laser with a built-in nonlinearity. High power, tunable THz radiation will be emitted via difference frequency generation, and the packaging will be optimized for thermal management and collection of phase-matched THz output. Intellectual Merit: The intellectual merit of this project lies in developing the core technologies and integration processes necessary to produce a multi-functional monolithic THz emitter. The various research topics necessary include modeling of intersubband gain, nonlinearity, and transport , thermal management, laser cavity nonlinearities, and efficient free space coupling of THz radiation. Successful integration onto a common platform will play a transformative role in the further development of multi-functional mid-infrared and THz optoelectronic integrated circuits. Broader Impacts: The broader impacts of this work will impact both scientific infrastructure and education. First, the small size of this source and potential for mass production may represent a future enabling technology for widespread access to the THz spectral region. This type of THz source has numerous applications in basic science, as well as in explosive and drug detection, security screening (T-ray imaging), astronomy/ astrophysics, and medical imaging. Progress in source development will be published and accessible to the general scientific community. Finally, aspects of the research will be used as classroom examples at Northwestern University and provide secondary research opportunities for undergraduates and local high school students.