Nonlinear optics of structured light carrying orbital angular momentum (OAM) has recently led to intriguing fundamental physical effects in light–matter interactions and advanced applications from classical imaging to quantum informatics. However, the mutual interaction between spatial mode and frequency conversions in nonlinear processes is still elusive. In this work, we go beyond only considering OAM and frequency in nonlinear structured light conversion and investigate the complex mode evolution in cascaded nonlinear frequency conversion and spatial astigmatic mode conversion. In particular, we unveil a generalized law of nonlinear structured light from experiments and theories, that the converted modes are highly related to the sequence of frequency and spatial mode conversions, obeying an inherent (non)commutative rule in which. This effect not only creates extended structured laser modes but serves as regular rules in nonlinear optics.

中文翻译：

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结构光激光器的频率-散光非对称非线性转换


最近，携带轨道角动量 （OAM） 的结构光非线性光学在光-物质相互作用中产生了有趣的基本物理效应，以及从经典成像到量子信息学的高级应用。然而，非线性过程中空间模式和频率转换之间的相互交互仍然难以捉摸。在这项工作中，我们不仅考虑了非线性结构光转换中的 OAM 和频率，还研究了级联非线性频率转换和空间散光模式转换中的复模演化。特别是，我们从实验和理论中揭示了非线性结构光的广义定律，即转换模式与频率和空间模式转换的顺序高度相关，遵循固有的（非）交换规则。这种效应不仅会产生扩展的结构化激光模式，而且在非线性光学中充当规则。