AI 中文总结
研究纳米尺度光热相互作用，开发耦合模式理论捕捉复杂瞬态现象，揭示最佳能量沉积和加热条件，以设计超表面为例展示其应用，为纳米光热相互作用提供见解，可用于多领域。
AI 中文摘要
纳米尺度系统中的光热相互作用已成为一种通用工具，可用于选择性热沉积和光学响应的稳健调谐，有从高温医疗到光信号切换和路由等众多应用。然而，目前缺少瞬态光热相互作用的综合理论。当光激发持续时间与热传输时间尺度可比时，开发这样的理论尤其具有挑战性。在此，我们开发了一种耦合模式理论，能捕捉各种纳米尺度系统中复杂的瞬态光热现象。我们还揭示了最佳能量沉积和加热的条件。以设计具有高对比度、高效温度和光学切换的超表面为例，展示了能在40纳秒内快速冷却到静止状态。我们的理论不仅能精确控制瞬态温度分布和光学响应，还能为纳米尺度的光热相互作用提供深刻的物理见解，可应用于从医疗到有源光子学和制造等多个领域。
英文摘要
Photothermal interaction in nanoscale systems has emerged as a versatile tool for selective heat deposition and robust tuning of optical responses with a myriad of applications from hyperthermal medical treatment to switching and routing of optical signals. However, to date a comprehensive theory of transient photothermal interaction is missing. Development of such a theory is particularly challenged when optical excitation duration is comparable to the timescale related of heat transport, an emergent regime with a mutually interconnected transient interplay of light abortion and heat-induced change of optical responses. Here, we develop a coupled mode theory that captures intricate transient photothermal phenomena in a wide range of nanoscale systems. We further reveal conditions for optimal energy deposition and heating. As an example scenario we apply our model to design metasurfaces with high contrast and efficient temperature and optical switching, demonstrating fast cooling to the rest state (within 40 ns). Beyond exquisite control of both transient temperature profiles and optical responses, our theory offers deep physical insights onto photo-thermal interaction at the nanoscale which can find use in variety of fields from medical treatment to active photonics and manufacturing.
