基于非共线位相匹配光的非线性产生和调控

Phase-matching is one of the important aspect in nonlinear optics, because it determines whether the new optical fields radiating from the nonlinear polarization would get coherently interfered. In the proposed project, we take non-collinear phase-matching as the thread, based on the different two-dimensional wave-vector mismatches for the several types of non-collinear phase-matching geometries, carrying out the research on nonlinear generation and manipulation of light. Activated by the promising application in quantum sensing, we will take effect to look into the new mechanism for the Cherenkov type optical parametric generation process, and try to realize it experimentally. We will also carry out the research on nonlinear manipulation of the wave front of light in optical waveguides based on Cherenkov type phase-matching and quasi-phase-matching, and subsequently developing new components and devices in the area of integrated photonics. Owning to the special distribution of the optical field in the transverse cross section, we will focus on the characteristics during non-collinear frequency conversions of structured light and try to find the figure out the possible new optical effects. To sum up, through the implementing this project, we hope to disclose the physical essence of some nonlinear optical processes, providing new ideas for nonlinearly manipulating light, as well as developing new applications, within the frame of non-collinear phase-matching.

非线性光学中的重要问题之一是位相匹配，它决定了非线性极化所辐射的新光场能否得到相长叠加。本项目以非共线位相匹配为主线，立足于几种非共线位相匹配方式中不同的二维波矢失配情况，围绕光的非线性产生和调控展开研究。以Cherenkov型光参量产生过程在量子传感等方面的可能应用为牵引，探索波导中Cherenkov型光参量产生过程的发生机制，寻求实验实现方案；基于Cherenkov型位相匹配和准位相匹配，在波导中开展辐射光的非线性波前调控研究，开发新型集成光学功能器件；此外，基于结构光束在横截面上的特殊光场分布，我们将结构光束的频率转换研究从共线拓展至非共线，希望发现新现象并研究其机制。总之，通过项目的实施，希望能在非共线位相匹配的框架下，揭示一些非线性光学过程的物理本质，提供光的非线性调控新思路，并发展新的应用。

本项目基于非共线位相匹配的几种相位匹配构型，开展了光的非线性产生和调控研究。项目执行完毕，发展了光学超晶格中非线性光场研究的基本理论方法和实验技术方案。在以下几个方面取得了研究进展：一是拓展了非线性光学的相位匹配理论，在一维周期光学超晶格中，通过共线倍频、布拉格型、拉曼-内斯等三种相位匹配方式，在实验上首次揭示了非线性频率转换过程中的转移规律。二是通过合作研究，发展了飞秒激光铁电畴擦除技术，制备出了第一块铌酸锂三维非线性光子晶体，演示了三维的准相位匹配倍频，设计并实现了高效的非线性光束整型器件。三是提出了基于非线性Cherenkov型相位匹配形式的集成化倍频涡旋光发射器，产生倍频涡旋光的拓扑荷数受到微环谐振腔的序数和角向极化周期的同时调制。通过项目的实施，希在非共线位相匹配的框架下，揭示一些非线性光学过程的物理本质，提供光的非线性调控新思路，并发展新的应用。