ADVANCED COOLING TECHNOLOGIES INC — Department of Defense STTR Phase I: AF14-AT27

Description

ABSTRACT: Recently quantum cascade lasers (QCLs) and interband cascade lasers (ICLs) have progressed steadily in the 3.5 10 m range with optical powers < 0.5 W. However, these devices rely on complicated band alignment and large numbers of repeating quantum wells which pose significant challenges in device fabrication. Furthermore, the sub-Watt power limitation and poor wall-plug efficiencies (WPE) of these devices precludes their use in the aforementioned applications involving at-distance operation. This shortcoming of QCL and ICL devices makes the simpler devices, such as type-I quantum well lasers, attractive for applications. Type-1 quantum well lasers, however, have not yet achieved Watt-level power output at wavelengths longer than 2.5 m due to several deleterious effects such as poor hole confinement, limited wavelength coverage due to miscibility gap, and increased Auger current losses. A very attractive solution to these problems is to dope the III-As and III-Sb materials with bismuth, however a rigorous understanding of Bi-doped materials is still missing. We propose a physics-based modeling approch for mid-IR bismides semiconductor lasers to achieve Watt-level operation at 3-5 microns. The Phase I effort is to establish a physics-based model for Bi-doped semiconductors and providing quantitative predictions for laser device design. BENEFIT: In addition to addressing Air Forces need for developing rigorous understanding of atom-up physics and behavior of mid-IR semiconductor devices, the proposed research will also be beneficial to commercial applications in area of telecommunications, chemical effluent sensing and medical diagnostics. The fundamental insights gained in this work and the resulting toolkit (project outcome) will provide a quantitative simulation for understanding the gain/loss behavior of laser structures producing Watt level output at 3-5 microns. The tool will also enable improvements to design process of future type-1 quantum well lasers. ACT will commercialize the developed tool by partnering with DoD prime contractors and commercial chemical diagnostic equipment developers.