The objective of this program is to develop room-temperature terahertz semiconductor Raman lasers based on giant Raman nonlinearities associated with intersubband transitions in semiconductor superlattices. The new devices are expected to operate at room temperature because the Raman gain does require population inversion across the low-energy terahertz transition. Giant values of Raman nonlinearity will allow using midinfrared quantum cascade laser butt-joined to the Raman section for pumping. Such device configuration will result in millimeter-sized electrically-pumped terahertz semiconductor laser sources.
The intellectual merit of this research is to explore a novel and highly promising approach to produce the first room-temperature terahertz semiconductor laser source. This work will enhance our understanding of optical nonlinearities and intersubband electron dynamics in semiconductor nanostructures. This project promises significant advances in state of the art terahertz sources, yielding compact semiconductor devices operating at room temperature, at higher power, and with new functionalities such as broadband electric tunability.
The broader impacts are also significant. The proposed research lies at the intersection of the optoelectronics, nonlinear optics, and physics of semiconductors. This combination of disciplines offers a unique educational environment for the students involved in the project. Knowledge and techniques developed during research will be incorporated into graduate- and undergraduate-level courses, disseminated through publications, technology transfer, and the research groups, websites. Room-temperature terahertz semiconductor lasers developed as a result of this program are expected to transform existing terahertz instrumentation with applications ranging from high-resolution spectroscopy and local oscillators for radio astronomy to terahertz remote sensing and imaging.
