THz Quantum Cascade Lasers: Simulation of GaN-Based Active Regions and Fabrication of Integrated Waveguide Probes
- Author(s): Naghibi Mahmoudabadi, Partia
- Advisor(s): Williams, Benjamin S
- et al.
The terahertz region of electromagnetic wave spectrum spanning from 300 GHz to 10 THz (the transition from electronics to photonics) has recently attracted considerable attention based on its numerous applications in different fields. Quantum cascade lasers (QCLs) have been developed in the past ten years as important sources of terahertz radiation. However, there still remain challenges to overcome such as room-temperature operation, efficient out-coupled power and directive radiative beam pattern. Achieving these goals will make THz QCLs very special sources of light to be utilized in broad range of applications in astronomy, biology, medical imaging, etc. This research tackles the aforementioned challenges in two sections. First, it targets the room-temperature issue by focusing on active region engineering and utilizing GaN/AlGaN quantum wells instead of the conventional GaAs/AlGaAs heterostructure QCLs. Second, it introduces a novel approach in waveguide engineering by harnessing the transmission line theory in order to improve the out-coupled power and radiation beam pattern.