具有光子带隙的亚波长微纳结构可以实现对辐射传输的深入、灵活的调节和操控，在构建新型微纳尺度热辐射调控器件方面具有重要的理论研究价值和广阔的应用前景。然而，目前对于亚波长微纳结构中关键的模态耦合机制的研究甚为不足，缺乏关于模态耦合机制对光子带隙影响机理的深入、系统的研究，也缺乏基于模态耦合机制的辐射特性理论模型，无法为亚波长微纳结构中光子带隙与辐射特性的主动设计与调控提供理论支撑，实验方面也缺乏对模态耦合机制的直接揭示。因此，本课题将从电磁波理论出发，对亚波长微纳结构中模态耦合机制进行系统探究，揭示模态耦合机制对其中光子带隙的影响机理，建立基于模态耦合机制的辐射特性理论模型，并进行实验研究。在此基础上，本课题将基于模态耦合机制及相应的辐射特性模型，通过设计特定的周期性排布方式的亚波长微纳结构，对光子带隙与辐射特性进行主动调控，实现高性能的亚波长微纳结构热辐射调控器件。

Subwavelength micro/nanostructures with photonic band gaps can achieve an in-depth and flexible control of thermal radiation transport, which are of both scientific and practical significance in exploring next-generation micro/nanoscale thermal radiation control devices. However, a systematic investigation of the mode coupling mechanism (MCM) in subwavelength photonic band gap micro/nanostructures is still missing, which is critical to the photonic band gaps and radiative properties. A radiative property model considering the MCM is still not available, which hinders the active design and manipulation of the band gaps and radiative properties. An experimental investigation of the MCM is also lacking. Therefore, based on electromagnetic wave theory, this project will carry out a systematic study on the MCM in subwavelength photonic band gap micro/nanostructures, and establish a theoretical model of radiative properties. Moreover, a comprehensive experimental study will be conducted to examine the role of MCM. On the basis of theoretical and experimental studies, this project will design subwavelength photonic band gap micro/nanostructures with specific spatial arrangements of structure units, in order to achieve an active control of the MCM and thus radiative properties. Afterwards, a high-performance device composed of subwavelength micro/nanostructures with two photonic band gaps will be designed and experimentally characterized.