Terahertz (THz) metasurfaces have opened up a new avenue for the THz wavefront modulation. However, high-efficient and low-cost fabrication of THz metasurfaces remains a great challenge today. Here, quasi-capsule-shaped polarization-multiplexed holographic THz metasurfaces were printed by a beam-shaped femtosecond laser. The laser beam was spatially modulated by holograms of optimized cylindrical lens loaded on a spatial light modulator (SLM). The size of quasi-capsule apertures can be exquisitely and flexibly controlled by adjusting the focal length in holograms, pulse energy, and pulse number. Based on near-field diffraction and Burch encoding, an array of 100 × 100 basic unit apertures were initially designed, and a polarization-multiplexed THz metasurface was finally printed with a dimension of 8 mm × 8 mm. The function of polarization multiplexing was demonstrated, by which two kinds of images were reconstructed in response to X and Y-polarization THz waves, respectively. The present work highlights a great leap in fabrication method for THz metasurfaces and hopefully stimulates the development of miniaturized and integrated THz systems.

中文翻译：

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准胶囊形全息太赫兹超表面的光束形飞秒激光打印

太赫兹（THz）超表面为太赫兹波前调制开辟了一条新途径。然而，太赫兹超表面的高效、低成本制造仍然是当今的巨大挑战。在这里，准胶囊形偏振复用全息太赫兹超表面是由光束形飞秒激光器打印的。激光束通过装载在空间光调制器（SLM）上的优化柱面透镜的全息图进行空间调制。通过调节全息图中的焦距、脉冲能量和脉冲数量，可以精细灵活地控制准胶囊孔径的大小。基于近场衍射和Burch编码，初步设计了100×100个基本单元孔径阵列，最终打印出尺寸为8 mm×8 mm的偏振复用太赫兹超表面。演示了偏振复用的功能，通过该功能分别响应X和Y偏振太赫兹波重建两种图像。目前的工作凸显了太赫兹超表面制造方法的巨大飞跃，并有望刺激小型化和集成太赫兹系统的发展。