In this paper, we demonstrate giant and tunable polarization selectivity of circularly polarized light (CPL) in transmission and reflection modes simultaneously by using photosensitive silicon-based zigzag metasurface. At 3.42 THz, the metasurface provides circular dichroism of transmission/reflection (CDT/CDR) of 0.89/−0.83 for forward-incident CPL and −0.86/0.69 for backward-incident CPL. Multipole expansion and Jones matrix deduction are performed to analyze the physical mechanism of polarization selectivity. To verify the actual control effect of polarization selectivity, a dynamic chiral imaging utilizing the proposed structure and its enantiomer is provided. By applying extra optical pumping to silicon, the switching between showing and hiding pre-designed pattern in transmission field is realized without refabricating the structures. The proposed metasurface with high-efficiency circular polarization selectivity has profound implications for photonic integrated devices.

在本文中，我们展示了巨大且可调谐的偏振选择性 通过使用光敏硅基锯齿形超表面，同时实现透射和反射模式的圆偏振光 (CPL)。在 3.42 THz 时，超表面提供的透射/反射圆二色性 (CDT/CDR) 对于前向入射 CPL 为 0.89/-0.83，对于后向入射 CPL 为 -0.86/0.69。通过多极展开和琼斯矩阵推导分析了偏振选择性的物理机制。为了验证偏振选择性的实际控制效果，提供了利用所提出的结构及其对映异构体的动态手性成像。通过对硅施加额外的光泵浦，无需重新制造结构即可实现在传输场中显示和隐藏预先设计的图案之间的切换。