Light–matter interaction is a key branch of photonics/optical material science. As the research emphasis in recent years has shifted from microscale toward nanoscale, light–matter interaction within extreme dimensions raises new challenges as well as opportunities. However, because of the classic diffraction limit of conventional optics, coupling and confinement of light into deep‐subwavelength volume is usually very challenging, resulting in difficulties in exploring the light–matter interaction within ultrathin and ultrasmall dimensions. Based on recent advances in theoretical modeling, nanomanufacturing and experimental validation efforts, unique features have been recognized. Here, recent key progresses of light–matter interaction within extreme dimensions are summarized and future directions based on new combinations of materials, structures, nanomanufacturing, and applications are discussed, ranging from quantum plasmonics, nonlinear optics, to optical biosensing.

中文翻译：

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极限尺寸内的光-物质相互作用：从纳米制造到应用

光与物质的相互作用是光子/光学材料科学的重要分支。随着近年来研究重点从微米级向纳米级转移，极端尺寸内的光-物质相互作用带来了新的挑战和机遇。但是，由于常规光学器件的经典衍射极限，将光耦合和限制到深亚波长体积通常非常困难，从而导致难以探索超薄和超小尺寸内的光-质相互作用。基于理论建模，纳米制造和实验验证工作的最新进展，人们已经认识到独特的功能。在此，总结了在极端尺寸范围内光物质相互作用的最新关键进展，并基于材料，结构，