Abstract. Optical hierarchical sorting has attracted significant attention in recent years. The existing approaches use either complex numerical calculation or computer-aided experimental tools for optical hierarchical sorting. We proposed a method to perform hierarchical sorting, which is computationally simple and does not need computer aid. In particular, we employed a focused optical vortices array (FOVA), which is generated and focused by a spiral phase plate array (SPPA) and a microlens array, respectively. We designed different heights for the spiral phase plate in different columns of the SPPA. This enabled different columns of the FOVA to carry different topological charges and consequently possess different capture capabilities. To realize hierarchical sorting, we exploited the properties of FOVA by deploying it in a microfluidic chamber containing particles of various sizes. The four columns of the FOVA formed four corresponding capture regions in the flow area of the particles. From our theoretical analysis and numerical results, we observed that particle sizes in the range of 1 to 582 nm could be sorted. Our approach provides a theoretical framework that can be readily employed in experiments for optical hierarchical sorting.

中文翻译：

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基于螺旋相位板阵列夫琅禾费衍射场的粒子光学分级分选研究

摘要。近年来，光学分级分选引起了极大的关注。现有的方法要么使用复杂的数值计算，要么使用计算机辅助的实验工具进行光学分层排序。我们提出了一种执行分层排序的方法，该方法计算简单且不需要计算机辅助。特别是，我们采用了聚焦光学涡流阵列 (FOVA)，它分别由螺旋相位板阵列 (SPPA) 和微透镜阵列产生和聚焦。我们为 SPPA 不同塔中的螺旋相板设计了不同的高度。这使得 FOVA 的不同列能够携带不同的拓扑电荷，因此具有不同的捕获能力。实现分层排序，我们通过将 FOVA 部署在包含各种尺寸颗粒的微流体室中来利用 FOVA 的特性。FOVA 的四列在粒子的流动区域中形成了四个对应的捕获区域。根据我们的理论分析和数值结果，我们观察到可以分选 1 到 582 nm 范围内的粒径。我们的方法提供了一个理论框架，可以很容易地用于光学分层排序的实验。