The semiconductor-based Quantum Cascade Laser (QCL) offers several key advantages over gas lasers, solid-state lasers, and other semiconductor-based mid-infrared lasers. While the QCL has historically operated best in the λ ~ 7-9 μm range using InP-based materials, a major challenge has been to achieve a high-power, room-temperature continuous-wave (CW) operation at shorter wavelengths. Historically, short wavelength performance has been limited due to problems of electron confinement, intervalley leakage, waveguide losses, and high power density. The goal of this work is to overcome these limitations using strain-balanced GaInAs-AlInAs epitaxial materials on InP as well as enhanced thermal management to extend the QCL operating range to the short wavelength limit (λ ~ 3 μm) with high power high temperature operation. This work begins with a discussion of the limitations of lattice-matched QCL growth and the physical background of strain effects on band structure. The fundamental problems with the GasMBE growth and characterization of strained GaInAs-AlInAs-InP materials are addressed. Thermal modeling and package design work is presented to address high power density problems at high temperatures. Experimental laser testing results are presented, including reliability testing. Finally, to demonstrate the commercial potential of the technology developed in this work, an initial system prototype of a widely tunable external cavity (EC-QCL) is presented.

Last modified

• 09/14/2018

Creator

• Allan Joseph Evans

DOI

• https://doi.org/10.21985/N2M14Z

Subject

• Electrical and Computer Engineering

Keyword

• Gas Source Molecular Beam Epitaxy MBE
• intersubband
• Compound Semiconductor
• Mid-Infrared Laser
• InP
• Quantum Cascade Laser

Date created

• 2008-05-22

Resource type

• Dissertation

Rights statement

• In Copyright