论文标题
石墨薄膜超快和非线性光学特性的第一原理研究
First-principles study of ultrafast and nonlinear optical properties of graphite thin films
论文作者
论文摘要
我们从理论上研究了基于第一原理时间依赖性密度功能理论的石墨薄膜的超快和非线性光学特性。我们首先在强脉冲电场下计算石墨单元中的电子动力学，并探索石墨的瞬态光学特性。结果表明，石墨的光学响应表明，从传导到绝缘阶段的某个强度范围内的一定强度范围内的突然变化。它也作为可饱和吸收，即从电场到电子的能量转移中的饱和度。接下来，我们通过同时解决电子和电磁场的耦合动力学来研究石墨薄膜中的光传播。可以观察到，可饱和吸收在空间区域的衰减小衰减中表现在传播中，其中电场幅度约为$ 4 \ sim 7 \ times 10^{ - 2} $ v/angstrom。
We theoretically investigate ultrafast and nonlinear optical properties of graphite thin films based on first-principles time-dependent density functional theory. We first calculate electron dynamics in a unit cell of graphite under a strong pulsed electric field and explore the transient optical properties of graphite. It is shown that the optical response of graphite shows a sudden change from conducting to insulating phase at a certain intensity range of the applied electric field. It also appears as a saturable absorption, the saturation in the energy transfer from the electric field to electrons. We next investigate a light propagation in graphite thin films by solving coupled dynamics of the electrons and the electromagnetic fields simultaneously. It is observed that the saturable absorption manifests in the propagation with small attenuation in the spatial region where the electric field amplitude is about $4 \sim 7 \times 10^{-2}$ V/Angstrom.
