半导体带间级联激光器研究进展

半导体带间级联量子阱是实现3~5μm波段中红外激光器的重要前沿,其在半导体光电器件技术、气体检测、医学医疗以及自由空间光通信等诸多领域具有重要科学意义和应用价值。半导体带间级联量子阱发光机理是以二类量子阱中的电子与空穴的带间辐射复合发光为主导,再通过电子注入区与空穴注入区形成级联放大,实现多个量子阱周期内电子与空穴的重复利用。本文综述了半导体带间级联激光器从提出能带结构、外延材料到器件制备技术的发展历程,剖析了器件结构各功能区基本概念和工作原理,介绍了器件结构设计与制备工艺技术难点的里程碑突破,详细解释了载流子再平衡、分别限制层等设计,最后展望了半导体带间级联激光器的发展方向和趋势。     

GaSb-based type-I quantum well cascade diode lasers emitting at nearly 2-μm wavelength with digitally grown AlGaAsSb gradient layers

We report a GaSb-based type-I quantum well cascade diode laser emitting at nearly 2-μm wavelength. The recycling of carriers is realized by the gradient AlGaAsSb barrier and chirped GaSb/AlSb/InAs electron injector. The growth of quaternary digital alloy with a gradually changed composition by short-period superlattices is introduced in detail in this paper. And the quantum well cascade laser with 100-μm-wide, 2-mm-long ridge generates an about continuous-wave output of 0.8 W at room temperature. The characteristic temperature T₀ is estimated at above 60 K.