光子时间界面处的共振增强时间反射
Resonance-Enhanced Time Reflection at Photonic Temporal Interfaces
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中文总结 AI 辅助
本文提出共振辅助机制，利用时间界面前分散介质中的极化能量与调制系统能量，在临界条件下实现比传统等离子体调制强数个数量级的时间反射，并通过等离激元结构共振在氧化镉中预测超三个数量级的增强，为强时间散射提供新途径。
中文摘要 AI 辅助
光子时间界面能够实现对光场的动态控制，然而在光学频率下实现强时间反射仍然具有挑战性，因为传统方法要求在超快时间尺度上对材料折射率进行大幅改变。在此，我们提出一种共振辅助机制，该机制同时利用时间界面之前分散介质中积累的极化能量以及调制系统所提供的显著增强的能量。我们证明，在特定的临界条件下，快速提高材料共振频率所产生的强时间反射功率流密度比传统等离子体频率调制所提供的高出数个数量级。为了在光学系统中实现这一机制，我们确定了基于介电和等离激元结构共振的两条路径。对于等离激元路径，我们开发了一种导电氧化物圆柱阵列的解析有效介质模型，其中局域表面等离激元共振将组成的德鲁德响应转变为几何可调的等效洛伦兹响应。以氧化镉作为代表性材料，我们预测，在相同的适度等离子体频率调制下，即使存在实际损耗，其求和反射模式功率系数相对于相同均匀材料也增强了超过三个数量级。这些发现确立了空间共振工程作为一条有效途径，可在降低对材料固有可调性要求的同时实现强时间散射。
英文摘要
Photonic temporal interfaces enable dynamic control of light fields, yet strong time reflection at optical frequencies remains challenging because conventional approaches demand large material refractive-index changes on ultrafast timescales. Here, we introduce a resonance-assisted mechanism that harnesses both polarization energy accumulated in a dispersive medium prior to the temporal interface and strongly increased energy supplied by the modulation system. We show that, under a specific critical condition, rapidly increasing the material resonance frequency yields orders-of-magnitude stronger time-reflected power flux density than what conventional plasma-frequency modulation provides. To implement this mechanism in optical systems, we identify two routes based on dielectric and plasmonic structural resonances. For the plasmonic route, we develop an analytical effective-medium model of conducting-oxide cylinder arrays, in which localized surface-plasmon resonances transform the constituent Drude response into a geometrically tunable effective Lorentz response. Using cadmium oxide as a representative material, we predict an enhancement exceeding three orders of magnitude in the summed reflected-mode power coefficient relative to the same homogeneous material under the same modest plasma-frequency modulation, even in the presence of realistic losses. These findings establish spatial resonance engineering as an effective route to strong temporal scattering with reduced demands on intrinsic material tunability.
发表机构
- College of Physics and Optoelectronic Engineering, Harbin Engineering University（哈尔滨工程大学物理与光电工程学院）
- Department of Electronics and Nanoengineering, Aalto University（阿尔托大学电子与纳米工程系）
- TUM School of Computation, Information and Technology, Technical University of Munich（慕尼黑工业大学计算、信息与技术学院）
- Department of Physics and Mathematics, University of Eastern Finland（东芬兰大学物理与数学系）
- Institute of Theoretical Solid State Physics, Karlsruhe Institute of Technology（卡尔斯鲁厄理工学院理论固体物理研究所）
- Institute of Nanotechnology, Karlsruhe Institute of Technology（卡尔斯鲁厄理工学院纳米技术研究所）
- Center for Integrated Quantum Science and Technology, Karlsruhe Institute of Technology（卡尔斯鲁厄理工学院集成量子科学与技术中心）
机构由 AI 辅助整理，请以论文原文为准。
