U.S.-Federal Republic of Germany Cooperative Research: Nonlinear Optical Properties of Microstructures and Femtosecond Phenomena in Semiconductors

该奖项将授予Nasser Peyghambarian博士和Stephen W. Koch博士。亚利桑那大学与德意志联邦共和国法兰克福大学Hartmut Haug博士合作。他们对半导体微结构中的量子约束效应和短脉冲现象进行了实验和理论研究。实验工作将包括利用飞秒激光激发高激发半导体和半导体微结构的动力学研究。他们将在半导体带中产生光隙，并测量光谱空穴和载流子热化过程的演变。他们还将利用半导体微晶掺杂玻璃和蚀刻微结构研究半导体量子点的非线性光学特性。研究人员的理论研究将研究半导体微结构的线性和非线性光学特性，并分析量子约束效应。他们还将研究非平衡格林函数和量子力学速率理论在半导体中的相干过程和高场效应。他们将研究由强外场引起的半导体带的ac-Stark分裂，并将计算非平衡载流子分布的动力学。在强光激发下的半导体是固体物理中研究高电流非线性和非平衡过程的理想系统。该研究的目的是研究光波与各种材料，特别是空间尺寸减小的半导体之间非线性相互作用的基本现象。Peyghambarian博士在他的实验室里使用最先进的飞秒激光系统做了许多与这项研究相关的实验研究。Koch博士和Haug博士为合作提供了强大的互补理论专业知识。该研究对于理解在光信号处理中具有潜在应用价值的基本物理现象具有重要意义。

This award will enable Dr. Nasser Peyghambarian and Dr. Stephen W. Koch. University of Arizona, to collaborate with Dr. Hartmut Haug, University of Frankfurt, Federal Republic of Germany. They are carrying out experimental and theoretical studies of quantum confinement effects and short pulse phenomena in semiconductor micro-structures. Experimental work will include a study of the dynamics of highly excited semiconductors and semiconductor micro-structures using femtosecond laser excitation. They will induce gaps in semiconductor bands with light, and they will measure the evolution of the spectral hole and carrier thermalization process. They will also investigate nonlinear optical properties of semiconductor quantum-dots using semiconductor micro-crystallite doped glasses and etched micro-structures. The researchers' theoretical studies will examine the linear and nonlinear optical properties of semiconductor micro-structures and analyze quantum confinement effects. They will also study coherent processes and high-field effects in semiconductors with non-equilibrium Green functions and quantum-mechanical rate theories. They will investigate ac-Stark splitting of semiconductor bands caused by a strong external field and they will compute the dynamics of the nonequilibrium carrier distribution. A semiconductor under strong optical excitation is an ideal system to study nonlinear and non equilibrium processes of high current interest in solid state physics. The purpose of the research is to study the basic phenomena associated with nonlinear interactions between light waves and a variety of materials, most notably semiconductors with reduced space dimensions. Dr. Peyghambarian has done many of the experimental studies relevant to this research using a state of the art femtosecond laser system in his laboratory. Dr. Koch and Dr. Haug provide strong complementary theoretical expertise for the collaboration. The research is important for understanding fundamental physical phenomena which have potential applications in optical signal processing.