Excitons and Nonlinear Optical Effects in Wide Gap II-VI Semiconductor Superlattices

所提出的研究是对选定的半导体超晶格的非线性光学性质的研究。这项工作将特别关注II-VI化合物半导体（Zn, Mn）Se和（Cd, Mn）Te中激子共振附近的光诱导变化。这些材料的独特之处在于，强耦合的电子和磁激发在光学上是可获得的。提出的研究结合了两个新的和先进的研究方面，第一，在皮秒和飞秒时间尺度上使用复杂的瞬态光学技术，第二，新型超薄半导体层状超晶格结构的光谱学。这项工作的基本部分涉及在这样的时间尺度上描述大部分未知的激子动力学，而更多的应用部分侧重于增强高密度磁取向激子系统中所寻求的瞬态非线性。这项研究的长期影响包括超快光开关和逻辑元件的可能性。

The proposed research is an investigation into the nonlinear optical properties of selected semiconductor superlattices. The work will specifically focus on optically induced changes near the excitonic resonances in II-VI compound semiconductors such as (Zn, Mn)Se and (Cd, Mn)Te. These materials are unique in that strongly coupled electronic and magnetic excitations are optically accessible. The proposed studies combine two aspects of new and advanced research, first, the use of sophisticated transient optical techniques on picosecond and femtosecond timescale, and second, the spectroscopy of novel ultrathin semiconductor layered superlattice structures. The basic portion of the work involves the characterization of the largely unknown exciton kinetics on such timescale while the more applied part focuses on the enhancement of the sought transient nonlinearities in a high density magnetically oriented exciton system. The longer term impact of this research includes possibilities for ultrafast optical switches and logic elements.