Abstract Cylindrical vector beams (CVBs), being a special kind of beams with spatially variant states of polarizations, are promising in photonics applications, including high-resolution imaging, plasmon excitation, optical trapping, and laser machining. Recently, generating CVBs using metasurfaces has drawn enormous interest owing to their highly designable, multifunctional, and integratable features. However, related studies remain unexplored in the terahertz regime. Here, a generic method for efficiently generating terahertz CVBs carrying orbital angular momentums (OAMs) is proposed and experimentally demonstrated using transmission-type spatial-variant dielectric metasurfaces, which is realized by designing the interference between the two circularly polarized transmission components. This method is based on spin-decoupled phase control allowed by simultaneously manipulating the dynamic phase and geometric phase of each structure, endowing more degree of freedom in designing the vector beams. Two types of metasurfaces which respectively generate polarization-dependent terahertz vector vortex beams (VVBs) and vector Bessel beams (VBBs) are experimentally characterized. The proposed method opens a new window to generate versatile vector beams, providing new capabilities in developing novel, compact, and high-performance devices applicable to broad electromagnetic spectral regimes.

中文翻译：

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通过自旋解耦相位控制使用介电超表面生成太赫兹矢量光束

摘要 圆柱矢量光束 (CVBs) 是一种具有空间变化偏振态的特殊光束，在光子学应用中具有广阔的应用前景，包括高分辨率成像、等离子体激发、光捕获和激光加工。最近，使用超表面生成 CVB 因其高度可设计、多功能和可集成的特性而引起了极大的兴趣。然而，相关研究在太赫兹范围内仍未探索。在这里，提出了一种有效生成携带轨道角动量 (OAM) 的太赫兹 CVB 的通用方法，并使用透射型空间变化介电超表面进行了实验证明，这是通过设计两个圆极化透射组件之间的干涉来实现的。该方法基于自旋解耦相位控制，允许同时操纵每个结构的动态相位和几何相位，从而在设计矢量梁时具有更大的自由度。两种类型的超表面分别产生偏振相关的太赫兹矢量涡旋光束 (VVB) 和矢量贝塞尔光束 (VBB) 进行了实验表征。所提出的方法为生成通用矢量束打开了一个新窗口，为开发适用于广泛电磁频谱范围的新型、紧凑和高性能设备提供了新的能力。两种类型的超表面分别产生偏振相关的太赫兹矢量涡旋光束 (VVB) 和矢量贝塞尔光束 (VBB) 进行了实验表征。所提出的方法为生成通用矢量束打开了一个新窗口，为开发适用于广泛电磁频谱范围的新型、紧凑和高性能设备提供了新的能力。两种类型的超表面分别产生偏振相关的太赫兹矢量涡旋光束 (VVB) 和矢量贝塞尔光束 (VBB) 进行了实验表征。所提出的方法为生成通用矢量束打开了一个新窗口，为开发适用于广泛电磁频谱范围的新型、紧凑和高性能设备提供了新的能力。