Development of Mid-infrared and Far-infrared QCLs

Mid-infrared Quantum Cascade Lasers (mid-IR QCLs) have been rapidly developing andbecoming the practical mid-IR source for a multitude of applications. They are of particular technological interest as high efficiency lasers designed for the mid-wavelength infrared (MWIR) (3-5 μm), long-wavelength infrared (LWIR) (8-13 μm), and very-long-wavelength (VLWIR) (16-25 μm) atmospheric windows. Even though reasonably high efficiency has been achieved in mid-IR QCLs, a study of their efficiency based on an accurate transport modelling such as Non-equilibrium Green's Function (NEGF) is missing, probably due to its complicated and computationally intensive nature. In this work I focused on two subprojects; first is the development of high efficiency QCLs at 5 μm, and second is the design of a QCL that operates at 20 μm. For both projects, I present the design, bandstructure modeling and simulation, detailed micro-fabrication process, and characterization results and methods