Ultraviolet electroabsorption modulators based on III-nitride quantum wells

知识价值：该项目旨在开发工作在紫外波长的半导体光调制器，这是目前相当不发达的一系列设备，在非视距自由空间光通信，传感和光谱以及q开关脉冲激光器等领域具有重要应用。最近，研究人员基于GaN/AlGaN量子阱中的量子受限Stark效应，证明了紫外波长下的强电光响应。在这些结果的基础上，提出的研究将解决量子阱设计和器件几何？包括准波导和非对称法布里-珀罗调制器的发展？优化关键调制器参数，如对比度、导通损耗、驱动电压和带宽。此外，研究人员计划在a面GaN/AlGaN量子阱中展示基于偏振旋转的电吸收调制器，其中可以利用晶体结构的大面内各向异性来获得非常大的单通对比度。最后，对这些器件的高速性能进行了研究。更广泛的影响：拟议的活动将促进教育，通过培养学生在广泛的学科，包括量子阱工程，半导体外延生长，紫外线和高速光电器件制造和测试。为了提高该计划的有效性和范围，将强调大学生和高中实习生的参与。还计划建立一个期刊俱乐部和相关网站，以进一步促进iii -氮化光电子学重要领域的传播和思想交流。此外，提出的研究将导致新型器件的发展，这将扩大紫外光电子学的应用领域，例如光通信，光谱学和传感。更一般地说，这项工作将推进氮化物异质结构领域的知识状态（特别是关于非传统衬底平面上的量子阱和分布式布拉格反射器的制造），从而有利于这些材料的其他器件应用。

ECCS-0725786Theodore MoustakasBoston UniversityIntellectual merit: This project is aimed at the development of semiconductor optical modulators operating at ultraviolet wavelengths, a family of devices that is currently quite underdeveloped and that has important applications in areas such as non-line-of-sight free-space optical communications, sensing and spectroscopy, and Q-switched pulsed lasers. Recently the investigators have demonstrated a strong electro-optic response at ultraviolet wavelengths based on the quantum-confined Stark effect in GaN/AlGaN quantum wells. Building on these results, the proposed research will address the quantum-well design and device geometry ? including the development of quasi-waveguide and asymmetric-Fabry-Perot modulators ? to optimize key modulator parameters such as contrast ratio, on-state losses, drive voltage, and bandwidth. In addition the investigators plan to demonstrate electroabsorption modulators based on polarization rotation in A-plane GaN/AlGaN quantum wells, where the large in-plane anisotropy of the crystal structure can be exploited to obtain very large single-pass contrast ratios. Finally, the high-speed properties of these devices will be investigated. Broader impacts: The proposed activities will promote education through the training of students in a wide range of disciplines, including quantum-well engineering, semiconductor epitaxial growth, ultraviolet and high-speed optoelectronic device fabrication and testing. To increase the effectiveness and scope of this program, the involvement of undergraduates and high-school interns will be emphasized. A journal club and associated website are also planned to further contribute to the dissemination and exchange of ideas in the important field of III-nitride optoelectronics. Furthermore, the proposed research will lead to the development of novel devices that will expand the realm of applications of ultraviolet optoelectronics, e.g. for optical communications, spectroscopy, and sensing. More in general, this work will advance the state of knowledge in the area of nitride heterostructures (particularly with regards to the fabrication of quantum wells on non-traditional substrate planes and of distributed Bragg reflectors), thereby benefiting other device applications of these materials.