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特性的影响，对未来的光信息通信系统具有重要意义。为此，我们开始了与加州理工学院教授的合作研究。在本研究项目中，我们研究了(1)通过将量子阱激光器置于高磁场中，在半导体激光器中实现量子线和量子盒效应。(2)阐明量子盒激光器激光特性的极限；(3)量子线盒激光器的电子态和光学特性物理学，包括能带理论。来自东京大学的Arakawa教授、Sakaki教授、Ikoma教授、Sogawa先生和Takahashi先生以及来自加州理工学院的Yariv教授和Vahala教授参与了这个项目。此外，休斯研究所的Schulman博士，前加州理工学院访问研究员也加入了这个项目。更多的实验，我们使用了美国麻省理工学院francois Bitter Maenet实验室的高磁场设备，携带了来自日本和西海岸的样品，样品架，各种测量设备。在实验中，我们通过测量光致发光的各向异性和在高磁场中旋转量子阱激光器的激光特性来澄清量子箱效应。我们认为，我们的实验是成功的，并阐明了几个重要的特点。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、调制动态和光谱特性。此外，还对微结构激光器中存在的尺寸变化和非线性增益效应等问题进行了研究。利用紧密结合方法对预测激光特性的重要电子态进行了深入讨论。澄清了包括价带在内的量子线的能带结构，表明随着量子约束的增加，量子线的非抛物性和负有效质量性质更加明显。此外，我们还讨论了在量子线中加入应变效应的影响。此外，我们还就量子线和量子盒的制造技术的最新成果交换了技术信息。加州理工学院的团队正在研究二氧化硅图案衬底上的MOCVD生长，而东京大学的团队正在研究MBE和电子束辅助MOCVD生长的倾斜超晶格结构。两个小组现在都成功地实现了准量子线结构。然而，我们仍然需要一个突破来实现真正的量子线盒结构。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