标题： 通过拓扑腔中的热载流子增强石墨烯的太赫兹三次谐波产生 显示英文标题

标题： Enhanced THz third-harmonic generation in graphene via hot-carriers in a topological cavity

摘要： 石墨烯因其高三阶极化率和可调的光学特性，是一种在非线性太赫兹应用中很有前景的材料。 其由自由载流子热力学驱动的强非线性响应，促进了高效的三次谐波产生（THG），这可以通过使用共振超表面和等离激元结构进一步增强。 在本研究中，我们使用一个平台，在拓扑光子晶体的界面集成石墨烯条带，旨在提高低太赫兹频率下的THG。 为了准确捕捉非线性光学响应的温度依赖性，我们在太赫兹光激发下对石墨烯的光学和热力学响应进行耦合模拟，并在多物理场计算框架中引入光致热载流子效应。 这种方法揭示了载流子加热对THG的影响，提供了对非线性太赫兹过程更准确的描述，并揭示了之前被忽视的三阶电导率调制机制。 我们表明，载流子温度的升高在中等输入强度下促进了高转换效率，该设计在反射和透射模式下运行，适用于太赫兹范围内的先进超快光电设备。 显示英文摘要

摘要： Graphene is a promising material for nonlinear THz applications owing to its high third-order susceptibility and tunable optical properties. Its strong nonlinear response, driven by free-carrier thermodynamics, facilitates efficient third-harmonic generation (THG), which can be further enhanced using resonant metasurfaces and plasmonic structures. In this study, we use a platform that integrates graphene ribbons at the interface of topological photonic crystals designed to boost THG at low THz frequencies. To accurately capture the temperature dependence of the nonlinear optical response, we perform coupled simulations to model graphene's optical and thermodynamic responses under THz photoexcitation, incorporating photoinduced hot carrier effects within a multiphysics computational framework. This approach unveils the influence of carrier heating on THG, providing a more accurate description of nonlinear THz processes and revealing previously overlooked mechanisms of third-order conductivity modulation. We show that the elevated carrier temperature promotes high conversion efficiencies at moderate input intensities, within a design that operates in both reflection and transmission modes for advanced ultrafast optoelectronic devices in the THz regime.