We report on the characteristics of the terahertz waveform originating from both the nonequilibrium transport of photogenerated carriers and the longitudinal optical phonon-plasmon coupled mode in GaAs epitaxial structures having a built-in electric field. The terahertz waveforms at different pump fluences were analyzed by an equation for the coherent oscillations of plasmons and phonons in addition to a Monte Carlo simulation. We clearly distinguished the contributions of two transient phenomena to the terahertz waveform, which enables us to evaluate the relationship between various physical properties and the terahertz waveform. Based on the analysis, the sample structure dependence was discussed.

我们报告了源自光生载流子的非平衡传输和具有内置电场的 GaAs 外延结构中的纵向光学声子 - 等离子体耦合模式的太赫兹波形的特征。除了蒙特卡罗模拟外，还通过等离子体和声子的相干振荡方程分析了不同泵浦能量密度下的太赫兹波形。我们清楚地区分了两种瞬态现象对太赫兹波形的贡献，这使我们能够评估各种物理特性与太赫兹波形之间的关系。在此分析的基础上，讨论了样本结构依赖性。