Spatio-Temporal High-Speed Modulation of Semiconductor Optoelectronics by Lateral Electric Fields

这项提议解决了影响高频电子与光电子学和光电子学日益增长的集成领域的基本物理问题。我们的重点是半导体(量子井、线和点)在强直流下和高频(GHz-THz)电场中的光学性质，特别是在高频电场被电容施加的情况下，即不引入额外载流子的情况。我们将考虑的特殊现象涉及高频场中超快载流子动力学的相互作用，通过载流子分布的空间运动来屏蔽场，高频场的传播效应，以及载流子分布与光的相互作用。因此，这项工作将统一微观和宏观长度尺度以及飞秒到纳秒时间尺度上的动力学。我们的努力将主要是理论和计算方面的。我们将与我们的实验合作者一起，研究在高频场存在的情况下，光导体、半导体光放大器和垂直腔面发射激光器中载流子的空间动力学。在我们将探索的现象中，空间方面起着关键作用；一方面，我们将关注这种高频场如何对光电子学和光子学的运行产生不利影响，另一方面，我们将探索潜在的器件应用现象。潜在的应用包括超高带宽光开关，增强的光导太赫兹产生，超高速光调制器，半导体光发射器的横向模式控制，以及超高速光束控制。

This proposal addresses fundamental physical issues impacting the growing area of integration of high-frequency electronics with optoelectronics and photonics. Our focus is theoptical properties of semiconductors (quantum wells, wires, and dots) in the presence of strongdc and high-frequency (GHz-THz) electric fields.In particular, we will concentrate on cases where the high-frequency field is applied capacitively,i.e., it does not introduce additional carriers. The particular phenomena we will consider involvean interplay of ultrafast carrier dynamics in high-frequency fields, screening of the field bythe spatial motions of the carrier distributions, propagation effects of the high-frequency field,and the interaction of the carrier distributions with light. Thus, the work will unite both microand macroscopic length scales as well as dynamics on the femto to nanosecond timescales. Our effort will be primarily theoretical and computational. Together with our experimental collaborators, we will study the spatio-dynamics of carriers in photoconductors, semiconductor optical amplifier, and VCSEL's in the presence of the high-frequency fields. In the phenomena we will explore, the spatial aspects play a key role; on the one hand, we will be concerned with how such high-frequency fields adversely perturb the operation of optoelectronics and photonics, while on the other, we will explore potential phenomena for device applications. Potential applications include ultrahigh-bandwidth optical switching, enhanced photoconductive THz generation, ultrahigh-speed optical modulators, lateral mode control from semiconductor light emitters, and ultrahigh-speed beem steering.