基于动力学相位和Pancharatnam-Berry相位集成实现结构光场的产生和调控研究

Structured light field has been widely used in imaging, communication, medicine and other fields because of its unique phase, polarization and intensity distribution. At present, there are two main methods to generate structured light field: one is based on dynamic phase method, whereas it often needs to form interference loop with multiple dynamic devices, high requirements on experimental conditions, and easy to be affected by the outside world and large device volume. The other is based on Pancharatnam-Berry (PB) phase method. PB phase devices can change the polarization structure in micro-nano scale, which is suitable for optical integration. However, the structure of the devices is fixed, which limits the ability to generate and adjust the structured light field..In this project, we propose to carry out research on generation and regulation of structured light field based on optical integration of PB phase and dynamical phase. Firstly, a new theory of combining dynamic phase and PB phase to generate and control structured light field is proposed. On this basis, the transmission model of structured light field is established, and a new technique of adjusting and controlling structured light field is formed. Finally, the metasurface and dynamic phase devices are merged into a single device, and the typical structured light field is generated and controlled experimentally. The results not only can be used to flexibly generate and control the structured light field, but also can realize the plug-and-play micro-nano optical devices with composite functions, so it has important scientific significance and application value.

结构光场由于具有独特的相位、偏振和强度分布，已被广泛应用于成像、通信、医学等领域。目前产生结构光场的主要方法中，主要有两类：一类是基于动力学相位的方法，常常需要将多个动力学相位器件构成干涉环路，对实验条件要求高，且装置体积大。另一类是基于Pancharatnam-Berry（PB）相位的方法，PB相位器件能在微纳尺度改变偏振结构，适合于光学集成，但器件的结构固定，限制了调控结构光场的能力范围。.本项目提出开展基于动力学相和PB相集成，实现结构光场的产生和调控研究。首先，提出联合动力学相位和PB相位，产生和调控结构光场的新理论。在此基础上，建立结构光场传输模型，形成调控结构光场的新技术。最后，将超表面与动力学相位器件融合成单一器件，实验产生和调控典型的结构光场。研究结果不仅可用于灵活产生和调控结构光场，还能实现具有复合功能的、即插即用的微纳光学器件，因此具有重要的科学意义和应用价值。

首先，我们研究了基于动力学相位和Pancharatnam-Berry相位集成实现结构光场的产生和调控理论，并应用该理论指导设计了动力学相位和几何相位集成器件，用于特殊结构光场的产生和调控，如完美矢量涡旋光束。接着，根据Richards–Wolf矢量衍射理，推导了任意矢量涡旋光束的紧聚焦公式，并将该公式用于计算完美角向一阶涡旋光束和圆偏振环形光束的焦场，研究了其紧聚焦特性。紧聚焦的完美角向一阶涡旋光束，其焦场呈光针分布，焦场的横向半高全宽更小，焦场中心为准圆偏振分布，将焦场的这些特性，用于提升CARS体显微成像性能（横向分辨率、成像速度、抑制非谐振背景噪声）。进而，搭建了CARS体显微成像系统，实现了体成像。研究结果不仅为结构光场的产生提供了一条有效方法，而且方便拓展到基于结构光的显微成像技术中。