US-Korea Cooperative Research in Nonlinear Laser Spectroscopy of Semiconductor Heterostructures

9513197宋该奖项提供资金，允许俄克拉荷马州立大学激光研究中心宋振珠博士与韩国首尔国立大学物理系金大植博士开展为期24个月的半导体异质结构非线性激光光谱合作研究项目。在这项研究中，合作者计划调查最近在宽禁带材料中发现的强飞秒非线性，如锌硒、锌镉硒/锌硒量子井或GaN，这些材料在技术上具有越来越重要的意义。利用飞秒钛宝石激光器的二次谐波，在激子共振附近进行了飞秒混频实验。这些实验将在不同条件和不同衬底上生长的不同样品上进行不同的强度、偏振和温度。为了研究极性和带隙对飞秒非线性的影响，我们将研究GaN和InGaN的飞秒非线性。改变带隙对飞秒非线性的影响将通过在金刚石顶压室中进行加压四波混频实验来隔离。合作者希望通过这些和其他新颖的实验，获得宽带隙材料飞秒非线性的相干图像。通过他们的研究，合作者将扩大选定的半导体材料类别的知识前沿，其中一些可能具有有用的电子应用。合作者在他们提议的项目领域有相当多的补充研究经验。该项目与美韩合作科学计划的目标相关，该计划旨在通过交流科学信息、想法、技能和技术以及通过在互利问题上的合作来提高美国和韩国科学家和工程师之间的合作水平。参与该项目的韩国部分得到了韩国科学与工程基金会(KOSEF)的支持。***

9513197 Song This award provides funds to permit Dr. Jin-Joo Song, Center for Laser Research, Oklahoma State University, to pursue with Dr. Dai-Sik Kim, Department of Physics, Seoul National University, Korea, for 24 months, a program of cooperative research on nonlinear laser spectroscopy of semiconductor heterostructures. In this study, the collaborators plan to investigate recently found strong femtosecond nonlinearities in wide band gap materials such as ZnSe, ZnCdSe/ZnSe quantum wells, or GaN, that are of increasing technological importance. Femtosecond wave mixing experiments will be carried out near the exciton resonance using a second harmonic of a femtosecond Ti:Sapphire laser. These experiments will be performed varying intensity, polarization,and temperature on various samples grown under different conditions and on different substrates. In order to study the effect of polarity and band gap on the femtosecond nonlinearities, the femtosecond nonlinearities of GaN or InGaN will be investigated. The effect of changing the band gap on the femtosecond nonlinearities will be isolated by performing four- wave mixing experiments under pressure in a diamond anvil cell. The collaborators expect to obtain a coherent picture of femtosecond nonlinearities of wide bandgap materials through these and other novel experiments. Through their investigations, the collaborators will expand the frontiers of knowledge of the selected classes of semiconductor materials, some of which may have useful electronic applications. The collaborators have considerable complementary research experience in the field of their proposed project. This project is relevant to the objectives of the U.S.-Korea Cooperative Science Program which seeks to increase the level of cooperation between U.S. and Korean scientists and engineers through the exchange of scientific information, ideas, skills, and techniques and through collaboration on problems of mutual benefit. Korean part icipation in the project is supported by the Korea Science and Engineering Foundation (KOSEF). ***