硅基几何相位微纳结构的光波操控机理及其相控阵衍射器件的光束转换研究

It is known that Silicon based materials with geometric phased micro-nano structure are promising to manipulate the phase of lightwave accurately with very low transmission loss. Phased array diffractive optical elements, formed by such materials, can be used to manipulate and control incident lightwave point-by-point, which may provide the first-chosen solution to develop diffractive optical system with characteristics of high efficiency, high quality and high integration in the future. In this project, we plan to investigate the lightwave manipulation principles of Silicon based materials with geometric phased micro-nano structure, and then develop an innovative diffractive optical device to perform beam transformation. Pointing at such target, we firstly plan to start at investigating the characteristics of Silicon based materials with geometric phased micro-nano structure, from which we should build up the physical and mathmetical models of such materials. Based on the models, we next explore the propagation rules of electromagnetic field modes in the nano structure and then investigate the relations between the electromagnetic responses and the structural parameters of the materials. After that, we can find the optimized structural parameters of the materials. Secondly, we plan to use the optimized materials to form a phased arrayed diffractive optical device, the beam transformation model and evaluation system of such device will be built up. After that, the characteristics and working principles, optimization design theories and methods, fabrication processing, and experimental valiating of such device would be investigated in detail. With this project, the lightwave manipulation principles of geometric phased array diffractive element based on Silicon substrate can be recongnized. In applications, it can provide a highly efficient lightwave manipulation method in some key fields such as millitary defence, photonics integration and nano-lithography. Therefore, the proposed project has significant scientific importance and very high potential for real world applications.

硅基几何相位微纳结构材料具有精密的位相调节功能，并兼具电介质材料的低损特性。基于此材料设计的相控阵衍射器件，有望实现对入射光波点对点的精确操控，极有希望成为未来高品质、高效率、高度集成衍射光学系统的首选技术途径。项目拟深入研究硅基几何相位微纳结构材料对入射光波的调控机理，并据此发展一种实现光束变换的衍射光学新技术，基于此目标：1）从硅基几何相位微纳结构材料的特性研究着手，通过建立材料的物理和数学模型，摸索电磁场模式的传播规律，深入研究材料结构特征参数对其电磁响应特性的影响，筛选出最优材料结构形式；2）基于该材料构造新型相控阵衍射器件，建立器件的光束传输模型和评价体系，研究衍射器件的光束变换特性、优化设计理论和方法、工艺制备以及实验验证。项目理论上可厘清硅基几何相控阵衍射器件的光波调控机理，应用上可为军事国防、光子集成、纳米光刻等重点领域提供高效的光波操控手段，具有重要的科学价值和实际意义。

近年来，几何相位超表面由于具备连续精密的相位调控能力引起了广泛关注。早期的几何相位超表面研究主要基于金属材料，其固有的欧姆损耗限制了其进一步发展，因此低损的电介质材料成为超表面研究的新宠。项目组成功的将几何相位、硅基电介质材料以及传统衍射光学理论相结合，开辟了超表面材料实现光波调控的新思路，有望成为未来点对点相位控制、高效率、高质量、高集成度的衍射光学系统的首选解决方案。具体而言，项目组完成了对硅基几何相位微纳结构的理论分析和模型设计，深入研究了该结构对入射光波实现透反射调控的相关物理学原理，提出了“透反射+几何相位”的光波调控新模式，该模式为实现全空间的光波相位和能量调控开辟了一条全新的技术途径。通过灵活调控电介质纳米砖的米氏共振峰值波长，可设计出能实现任意透反比的新型硅基电介质几何相位超表面材料。在此基础上，本项目建立了硅基电介质几何相控阵光学衍射器件的光束传输模型，探索了硅基几何相控阵平面衍射器件的优化设计理论方法、加工制造和实验验证的等工作，成功地发展了一系列与硅基电介质几何相控相关的新概念平面衍射光学器件,包括全硅达曼光栅、傅里叶全息片、像全息片、透反射闪耀光栅、透反射式激光分束器和全空间随机光点云发生器等。总结而言，本项目发展了硅基几何相控阵平面衍射器件的优化设计理论，揭示了其工作机理和光束变换规律，实现了有效的模拟仿真、加工制造与器件应用。基于上述成果，项目组在包括Science Advances、ACS Nano、Light: Science & Advances在内的国际权威期刊上发表SCI论文14篇，申请国家发明专利70项，已授权发明专利15项，相关研究成果在光纤通信、光传感等诸多领域得到重要应用。