SBIR Phase I: Antimony-based Mid-Infrared Quantum Cascade Lasers

这个小型企业创新研究(SBIR)第一阶段项目将开发基于第二类砷化铟/氨基化镓/锑铝(InAs/GaSb/AlSb)量子阱结构的中红外(IR)量子级联激光器。这些激光器在中红外区域发射辐射，使化学传感、医疗诊断和工业过程控制等领域的商业产品成为可能。由于InAs和AlSb之间存在较大的导带偏移量，因此Sb基量子级联激光器的波长可以在较宽的光谱范围内进行定制。此外，由于第二类量子阱结构中的带隙阻塞，电子注入效率可以在不需要布拉格反射层的情况下获得接近100%的效率。这种材料系统的另一个优点是InAs中的电子有效质量很小，有助于降低声子散射率。因此，基于第二类InAs/GaSb/AlSb量子阱结构的子带间量子级联激光器是在室温下工作的紧凑、可靠、高效的中红外光源的理想候选者。第一阶段将涉及InAs/GaInSb/AlSb量子级联激光器的设计、分子束外延(MBE)生长、表征和优化，以展示其在低阈值电流和环境温度(或可用热电制冷器获得的温度)下运行的可行性。第二阶段将开发高性能的中红外量子级联激光器。第一个中红外半导体激光器有望在常温下工作在连续波(CW)条件下。这将使包括化学传感在内的几个领域的商业产品成为可能。一个例子是检测用于医疗诊断目的的甲醛和相关化合物的百万分之几(Ppb)水平。这些激光光源可能会发现其他商业和国防应用。

This Small Business Innovation Research (SBIR) Phase I project will develop mid-infrared (IR) quantum cascade lasers based on type-II indium arsenide/gallium anitmonide/aluminum antimonide (InAs/GaSb/AlSb) quantum well structures. These lasers emit radiation in the mid-IR region, enabling commercial products in fields including chemical sensing, medical diagnostics, and industrial process controls. The wavelength of Sb-based quantum cascade lasers can be tailored over a wide spectral range due to the large conduction band-offset between InAs and AlSb. In addition, because of the band-gap blocking in type-II quantum well structures, electron injection efficiencies near 100% can be achieved without requiring Bragg reflector layers. Another advantage of this material system is the small electron effective mass in InAs, contributing to reduced phonon scattering rates. Hence, the inter-sub-band quantum cascade lasers based on type-II InAs/GaSb/AlSb quantum well structures are excellent candidates for compact, reliable, efficient mid-infrared light sources operating at room temperature. Phase I will involve the design, molecular beam epitaxy (MBE) growth, characterization, and optimization of InAs/GaInSb/AlSb quantum cascade lasers to demonstrate their feasibility of operation at low threshold current and at ambient temperatures (or at temperatures accessible with a thermoelectric cooler). High performance mid-IR quantum cascade lasers would be developed in Phase II.The first mid-IR semiconductor lasers are expected to operate under continuous wave (cw) conditions at ambient temperatures. This would enable commercial products in several fields including chemical sensing. One example is detection, at the parts per billion (ppb) level, of formaldehyde and related compounds for medical diagnosis purposes. These laser sources will potentially find other commercial and defense applications.