GaAs-AlGaAs quantum cascade lasers: physics, technology, and prospects
GaAs-AlGaAs quantum cascade lasers: physics, technology, and prospects
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DOI：
10.1109/jqe.2002.1005405
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发表时间：
2002-08
影响因子：
2.5
通讯作者：
C. Sirtori;H. Page;C. Becker;V. Ortiz
中科院分区：
文献类型：
--
作者：
C. Sirtori;H. Page;C. Becker;V. Ortiz
近年来，GaAs-AlGaAs基量子级联（QC）激光器的性能有了显着提高。这些器件能够在室温下进行脉冲操作，并且在 Peltier 冷却器上操作时可提供可观的平均功率（/spl lambda//spl sim/9 /spl mu/m 时为 11 mW）。这种性能是通过增加异质势垒带偏移来抑制热激活载流子泄漏来实现的。我们证明，波长为 /spl lambda//spl ges/9 /spl mu/m 的 QC 激光器可以使用涵盖 Al/sub x/Ga/sub 1-x/As 整个成分范围的异质结构进行操作，而不会遇到卫星 X 最小值（x>45%）的潜在问题。此外，我们还介绍了这些器件的特殊特性，例如声子限制的温度依赖性、电和光学自振荡，以及利用这种紧密晶格匹配的材料系统的新颖设计概念。最后，我们讨论了器件制造的改进，以通过减少电流注入面积来降低工作电流。使用这项技术，可以设计设备来选择性地泵浦基本横向模式。因此，我们在整个当前操作范围内观察到单一空间模式操作。
In recent years, the performance of GaAs-AlGaAs-based quantum cascade (QC) lasers has improved markedly. These devices are capable of pulsed room temperature operation and can deliver respectable average powers (11 mW at /spl lambda//spl sim/9 /spl mu/m) operating on a Peltier cooler. This performance has been achieved by the suppression of thermally activated carrier leakage through increases in the heterobarrier band offset. We demonstrate that QC lasers, with wavelengths /spl lambda//spl ges/9 /spl mu/m, can operate using heterostructures encompassing the entire composition range of Al/sub x/Ga/sub 1-x/As, without encountering potential problems-of the satellite X-minima for x>45%. Furthermore, we present particular characteristics of these devices, such as a phonon-limited temperature dependence, electrical and optical self-oscillations, and novel design concepts that exploit this closely lattice matched material system. Finally, we discuss improvements in device fabrication to lower the operating current through a reduction of the area of current injection. Using this technology, devices can be designed to selectively pump the fundamental lateral mode. We, therefore, observe single spatial-mode operation over the entire current range of operation.