标题： 光学时间尺度调制的电磁响应 显示英文标题

标题： Electromagnetic Response for Modulation at Optical Time Scale

摘要： 快速的电磁响应在时间和空间上的调制在介质中产生了时间边界，并导致光的时间反射和时间折射，最终在调制的光学材料中形成了光子时间晶体，为光与物质的相互作用提供了新的领域，并具有从非共振光放大到可调激光的实际应用潜力。 然而，通常用于光子时间晶体及相关现象的方法，依赖于有效时变折射率的概念，在光学时间尺度上的超快调制领域本质上是不适用的。 我们开发了该领域中电磁响应和相关现象的适当理论描述，并不仅展示了与传统方法所得结论之间的定量差异，还展示了定性差异。 显示英文摘要

摘要： Rapid modulation of the electromagnetic response in both time and space creates temporal boundaries in the medium and leads to time-reflection and time-refraction of light and to the eventual formation of the photonic time crystal within the modulated optical material,, offering a new regime of light-matter interactions and a potential for practical applications, from non-resonant light amplification to tunable lasing. However, the conventional approach commonly used for the photonic time crystals and related phenomena that relies on the concept of effective time-dependent refractive index, is fundamentally unsuitable to this domain of ultra-fast modulation at optical time scales. We develop the appropriate theoretical description of the electromagnetic response and the resulting phenomena in this regime, and demonstrate not only quantitative but also qualitative differences from the conclusions obtained using the conventional approach.