New Type of Semiconductor Lasers with Quantum-Well Wire Structures and Quantum-Well Box Structures

研究量子线和量子盒结构对半导体激光器激光性能的影响对于未来的光信息和通信系统具有重要意义。为此，我们与加州理工学院的教授们展开了合作研究。在本研究项目中，我们进行了以下研究：(1)通过在强磁场中放置量子阱激光器来实现半导体激光器中的量子线和量子盒效应。(2)阐明量子盒激光器中激光特性的极限。(3)量子线和盒激光器的电子态物理和光学性质，包括能带理论。来自东京大学的荒川教授、Sakaki教授、Ikoma教授、Sogawa先生和Takahashi先生以及加州理工大学的Yariv教授和Vahala教授参与了这个项目。此外，休斯研究所的舒尔曼博士、加州理工大学的前访问研究员也加入了这一项目。对于强磁场…在更多的实验中，我们使用了美国麻省理工学院Frnacis Bit Maenet实验室的强磁场设备，携带了来自日本和西海岸的样品、样品保持器和各种测量设备。在实验中，我们通过测量量子井激光器在强磁场中的光致发光各向异性特性和旋转的激光特性，阐明了量子盒效应。我们相信我们的实验是成功的，并阐明了几个重要的特征。我们还研究了量子线和量子盒激光器的极限激光特性。讨论了阈值电流、调制动力学和光谱特性。此外，还研究了这类微结构激光器的尺寸变化和非线性增益效应等问题，并用紧束缚方法详细讨论了电子态对预测激光特性的重要作用。阐明了包括价带在内的能带结构，表明量子线的非抛物性和负有效质量性质随着量子限制的增加而更加明显。此外，我们还讨论了应变效应在量子线中的引入效应。此外，我们还交换了有关量子线和盒子制造技术的最新成果的技术信息。加州理工大学的研究小组正在研究二氧化硅图案衬底上的MOCVD生长，东京大学的研究小组正在研究MBE和电子束辅助MOCVD生长的倾斜超晶格结构。这两个小组现在都成功地实现了准量子线结构。然而，要实现真正的量子线和盒结构，我们还需要一个突破。较少

It is important to investigate effects of quantum wire and quantum box structure on lasing properties in semiconductor lasers for future optical information and communication systems. For this purpose we started cooperative research with professors of California Institute of Technology. In this research project, we do research on (1) Realization of quantum wire and quantum box effects in semiconductor lasers by placing a quantum well laser in a high magnetic field. (2) To clarify ultimate limit of lasing properties in the quantum box lasers (3) physics of electronic states and optical properties in quantum wire and box lasers including band theory. From University of Tokyo Prof. Arakawa, Prof. Sakaki, Prof. Ikoma, Mr. Sogawa, and Mr. Takahashi and from California Institute of Technology, Prof. Yariv and Prof. Vahala participated in this project. Moreover, Dr. Schulman, Hughes Research Institute, former visiting Researcher in Caltech also joined this project.For the high magnetic field … More experiment, we used high magnetic field facilities in Frnacis Bitter Maenet Laboratory of Massachusetts Institute of Technology, U.S.A. carrying samples, sample holders, various kinds of measurement equipment from Japan and west coast. In the experiment we clarified quantum box effects through the measurement of anisotropic properties of photoluminescence and lasing properties rotating the quantum well lasers in the high magnetic field. We believe that our experiment has been successful and clarified several important characteristics.We also study ultimate lasing characteristics of quantum wire and quantum box lasers. Threshold current, modulation dynamics, and spectral properties were discussed. In addition, several problems raised in such microstructure lasers such as size variation and nonlinear gain effects were investigated.Electronic states which are important for predicting lasing characteristics were also intensively discussed using the tight binding method. Band structures including the valence band of quantum wires were clarified, showing that the nonparabolicity and negative effective mass natures are more pronounced with the increase of the quantum confinement. Moreover, we discussed effects of incorporation of the strain effect in the quantum wires.Moreover we also exchange technical information on recent results on fabrication technology for quantum wires and boxed. Caltech group are studying MOCVD growth on SiO2 patterned substrates, while University of Tokyo group are investigating both tilted super lattice structures grown by MBE and electron beam assisted MOCVD. Both groups are now successful to achieve quasi-quantum wire structures. However, we still need one breakthrough for realizing real quantum wire and box structures. Less