We present the hybrid polarized vector optical fields (HP-VOFs) with multi singularities, and find that the purely longitudinal spin angular momentum (SAM) can partially transform into transverse SAM in tight focusing process. The concept of singularity phase is further proposed, providing additional degrees of freedom in modulating polarization configuration on the wave front. After introducing the singularity phase, purely transverse SAM is achieved for the tightly focused HP-VOF with multi singularities, indicating that the singularity phase can play a role as a catalyst to generate the purely transverse SAM in the tight focusing process. This is a new method to achieve purely transverse SAM, which would have potential applications in various areas including chip optical circuitry, optical quantum computing, and optical manipulation.

我们提出了具有多奇点的混合偏振矢量光场 (HP-VOF)，并发现纯纵向自旋角动量 (SAM) 在紧密聚焦过程中可以部分转换为横向 SAM。进一步提出了奇异相位的概念，为调制波前的偏振配置提供了额外的自由度。引入奇异相后，具有多奇异点的紧密聚焦HP-VOF实现了纯横向SAM，表明奇异相可以作为催化剂在紧密聚焦过程中产生纯横向SAM。这是一种实现纯横向SAM的新方法，在芯片光电路、光量子计算和光操纵等各个领域都有潜在的应用。