Faraday-Stark Optoelectronic Effect

本提案的目的是研究基于量子阱结构中法拉第旋转的一种新的光电效应。初步的工作表明，施加的电压可以用来控制法拉第旋转的程度。这种效应是新颖的，因为旋转的程度是由电场而不是磁场控制的。这可能导致电子控制的光开关和宽带光调制器。基于法拉第-斯塔克效应的光电器件只需要一个低开关电压（~伏特）和一个由永磁体提供的小直流磁场（1特斯拉）。光调制器的一些独特功能包括：*高带宽光调制，10^10 Hz；*在关闭状态下极低的传输，10^-5；40 dB调制深度；*兼容微光刻和波导。法拉第-斯塔克效应的初步实验是在加州大学圣巴巴拉分校（A.C. Gossard小组）生长的砷化镓量子阱样品上进行的。虽然这种结构没有针对法拉第-斯塔克效应进行优化，但麻省理工学院电子工程系（C. Fonstad小组）正在开发改进的结构。对于室温器件特别重要的是由II-VI磁性半导体结构制成的结构。它们将在我们自己的MBE机器中生长，该机器由美国国家科学基金会工程研究基金和美国电话电报公司的种子基金资助。各种II-VI和III-V材料结构将使用磁光实验进行研究。这些结果将有助于研究设计在感兴趣的波长上工作的设备的可能性。我们的目标是确定光电开关，调制器和电控光隔离器所需的限制和最佳条件。该研究项目将为学生提供工程、物理和材料科学方面的广泛教育。它还提供许多领域的实践培训，包括光学，磁性，半导体，MBE晶体生长，微加工，低维科学，高速电子，低温和高场磁体。这种基础广泛的教育可能会对研究生和本科生的未来就业产生影响。此外，光学领域的教育特别有价值，因为该领域的就业市场通常超过合格毕业生的数量。* * *

9623248 Heiman The aim of this proposal is to investigate a new optoelectronic effect based on Faraday rotation in quantum well structures. Preliminary work has demonstrated that an applied voltage can be used to control the degree of Faraday rotation. This effect is novel in the sense that the degree of rotation is controlled by an electric field as opposed to a magnetic field. This could lead to electronic control of light switches and wide bandwidth optical modulators. Optoelectronic devices based on the Faraday-Stark effect would require only a low switching voltage (~ volt) and a small dc magnetic field ( l tesla) supplied by a permanent magnet. Some unique features for optical modulators include: * high-bandwidth light modulation, 10^10 Hz; * very low transmission in the off-state, 10^-5; and 40 dB modulation depth; * compatibility with microlithography and waveguides. Initial experiments on the Faraday-Stark effect were performed on a GaAs quantum well sample grown at UC Santa Barbara (group of A.C. Gossard). Although this structure was not optimized for the Faraday-Stark effect, improved structures are being grown in the Electrical Engineering Department at MIT (group of C. Fonstad). Of particular importance for room temperature devices are structures made from II-VI magnetic semiconductor structures. These will be grown in our own MBE machine, which was fabricated with funding from an NSF Engineering Research Grant and seed funding from AT&T. A variety of II-VI and III-V material structures will be investigated using magneto-optical experiments. These results will be helpful in examining the possibilities for designing devices that operate at wavelengths of interest. Our ambition is to determine the limitations and optimum conditions required for optoelectronic light switches, modulators, and electrically-controlled optical isolators. This research program will provide students with a broad education in engineering, physics, and materi als science. It also provides hands-on training in many areas including optics, magnetism, semiconductors, MBE crystal growth, microfabrication, low-dimensional science, high-speed electronics, cryogenics, and high-field magnets. Such a broad-based education is likely to impact on the future employment of both graduate and undergraduate students. In addition, an education in the field of optics is exceptionally valuable since that job market usually exceeds the number of qualified graduates. ***