通信波段Sb化物量子点高特征温度激光机制与关键技术研究

Advanced performance laser diodes based on new materials and new devices structure is one of the hot topics. In this project, we will investigate a systematic study on the growth factors of the Sb quantum dots (QDs). We are going to grow and fabricate multi-layer quantum dots-in-well laser structure, in order to improve the uniformity of the QDs used as laser active region, and to increase the number of QDs effectively contributing to lasing. The use of multilayer QDs structures allows the stacking of QDs in the vertical direction via the stress interaction existing between the QDs layers called strain engineering. An appropriate choice of the thickness of the QDs spacer layer not only increases the QDs bulk density, but also effectively improves the QDs size and emission distribution uniformity, increases the carrier trapping capacity, improves the uniformity of QDs. By the Sb, it is possible to make the peak shift to the long wavelength, while using the dot-in-well to improve the temperature characteristics, the threshold and reducing purposes. Accordingly, the project intends to use multi-layer InGaSb QDs coupled with InGaAs quantum wells (QWs) structure, to achieve high-density, long-wavelength novel structure, with the p-type (Be) doping and variable Al components of graded-index waveguide and confined layers. The research will provide a new way of thinking and effective work methods, which is of great significance for further studies related to Sb-based mid-infrared semiconductor lasers in optics communication applications.

基于新材料和新器件结构的通信波段激光光源是光通信领域的研究热点之一，本项目面向光通信对高性能激光光源的需求，拟采用应变工程原理生长多层量子点与量子阱耦合结构，增大量子点的体密度和量子点尺寸，增加载流子的俘获能力，改善量子点分布的均匀性，达到提高激光器特征温度和降低阈值电流等目的。利用多层InGaSb量子点与InGaAs量子阱耦合结构，实现高密度、长波长InGaSb/InGaAs量子点/阱结构的外延生长，并对有源区进行P型（Be）掺杂。同时采取远离有源区高掺杂，临近有源区低掺杂的变掺杂和变Al组分的渐变折射率波导和限制层设计。在成熟的GaAs材料体系进行1.5μm波段InGaSb多层量子点激光器研究，探索GaAs基长波长、高特征温度的Sb基量子点激光器的相关问题，为制备新型量子点激光器提供新思路。

针对各种应用领域对于1.55μm半导体激光器的实际需求，本项目从基础的材料特性出发，以实现高温工作和提高输出功率为目标，从结构设计和制作技术两个方面入手，开展了高特征温度半导体激光器的研制工作，器件的主要性能达到了预期技术指标。.项目设计并优化了1.55μm高特征温度半导体激光器的结构，分析了半导体激光器的生长特性。根据理论分析，提出了Sb化物材料体系的激光器结构方案，并对其进行了高特征温度模式特性验证分析及其相关工艺实验研究。.设计出的高特征温度1.55μm半导体激光器结构，阈值电流135 A/cm2,实现了118K最大输出功率超过32 mW的输出特性。