研制Si基单片集成激光器在集成光电子学发展中具有重要意义。量子点结构材料由于具有独特的光电性质，在新型光电子器件方面显示出广阔的应用前景。我们已经完成的基金项目(60976015)中在InP基衬底上制备了高质量的InAs/InP量子点激光器，最近我们又成功制备了室温连续工作的高性能Ge基InAs/GaAs量子点激光器。本项目在前面研究工作基础上，利用双生长室分子束外延设备在Si衬底上先外延生长Ge，然后再生长InAs/GaAs量子点材料，深入研究大晶格失配材料晶格弛豫及缺陷形成机理，理解其中的物理机制，通过优化条件生长出高质量的Si基InAs/GaAs量子点激光器材料。在此基础上，制备量子点激光器器件，根据器件结果的反馈，开展材料与器件关系的研究，优化材料结构和器件工艺，提高器件特性，研制出室温连续激射Si基1.3微米量子点激光器。本项目的开展将为Si基激光器的光电子集成奠定良好的基础。

The realization of semiconductor laser diodes on Si substrates is very important for the creation of complex optoelectronic circuits. There is an increasing interest in employing low dimensional quantum dots (QDs) for optoelectronic devices, since QDs exhibit unique electronic and optical properties. In the past project (60976015), we have fabricated the high quality InAs/InP QD lasers grown on InP substrate. Recently, we have successfully fabricated high quality InAs/GaAs QD laser on a Ge substrate. Continuous-wave lasing was achieved at room temperature. In the current project, high quality Ge/Si materials will be grown by a dual chamber molecular beam epitaxy system through optimizing growth parameters. InAs/GaAs QD structures will be grown on the Ge buffer layer. The misfit strain relaxation in lattice-mismatched heterostructures and defect formation mechanism will be investigated. The physical mechanism behind them will be explored. Si-based InAs/GaAs QD lasers will be fabricated based on the high quality QD materials. The characteristics of QD laser devices will be studied in detail. The material growth and device fabrication technique will be optimized to further improve the device characteristics. The room-temperature continuous-wave operation of 1300nm InAs/GaAs QD lasers on silicon substrate will be achieved. The project will ultimately form the basis for the monolithic integration of lasers on Si platform.