We introduce and produce experimental optical beams exhibiting periodic skyrmionic polarization lattices at each transverse plane of propagation. These textures are meron lattices formed by tiles mapping hemispheres of the Poincaré sphere. All of the presented fields are combinations of a small number of plane waves. First, we propose square lattices with a Skyrme density (the Jacobian of the mapping between the Poincaré sphere and physical space) that oscillates in sign but whose intensity distribution is constant. Second, we present triangular lattices preserving the Skyrme density’s sign. Both lattices are invariant under propagation. Finally, we introduce a family of lattices with a uniform Skyrme density sign, composed of square tiles that map to the same hemisphere of the Poincaré sphere. In these lattices, the polarization state undergoes a uniform local periodic rotation during propagation, thus preserving the texture’s Skyrme density distribution.

中文翻译：

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传播不变光学 Meron 晶格


我们引入并产生了在每个传播横向平面上表现出周期性斯格明子偏振晶格的实验光束。这些纹理是由映射庞加莱球半球的瓷砖形成的梅隆晶格。所有提出的场都是少量平面波的组合。首先，我们提出了具有符号振荡但强度分布恒定的 Skyrme 密度（庞加莱球和物理空间之间映射的雅可比行列式）的方格。其次，我们提出保留 Skyrme 密度符号的三角晶格。两个晶格在传播下都是不变的。最后，我们引入了一系列具有统一 Skyrme 密度符号的晶格，由映射到庞加莱球的同一半球的方形图块组成。在这些晶格中，偏振态在传播过程中经历均匀的局部周期性旋转，从而保留纹理的 Skyrme 密度分布。