Self-complementary metasurfaces have gained significant attention due to their unique frequency-independent transmission and reflection properties and the possibility of the polarization transformation of plane waves. In this paper, we focus on the near-field spectrum to investigate, both theoretically and experimentally, the properties of surface waves supported by anisotropic self-complementary metasurfaces. We show that as a consequence of the electromagnetic Babinet’s duality, such a structure is hyperbolic for any frequency. We demonstrate the possibility of switching the canalization direction of surface waves with ultimately flat phase fronts for 90° by a very small frequency shift, paving the way to the extreme tunability and surface-wave routing. We reveal the polarization degree of freedom inherent to plane waves by demonstrating the all-frequency TE-TM polarization degeneracy of the surface waves along two principal directions. The results obtained open a plethora of opportunities for practical applications, including flat polarization devices, optical data-processing systems, sensing, holography and antennas.

中文翻译：

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自互补超表面上的表面波：全频双曲性、极端运河化和 TE-TM 极化简并

自互补超表面由于其独特的与频率无关的传输和反射特性以及平面波偏振变换的可能性而受到了极大的关注。在本文中，我们专注于近场光谱，从理论上和实验上研究各向异性自互补超表面支持的表面波的特性。我们表明，由于电磁巴比涅的二元性，这种结构对于任何频率都是双曲线的。我们证明了通过非常小的频移将具有最终平坦相位前沿的表面波的通道方向切换为 90° 的可能性，为极端可调性和表面波路由铺平了道路。我们通过展示表面波沿两个主要方向的全频 TE-TM 偏振简并性，揭示了平面波固有的偏振自由度。获得的结果为实际应用开辟了大量机会，包括平面偏振设备、光学数据处理系统、传感、全息和天线。