A terahertz isolator is demonstrated for the THz nonreciprocal reflections in the magneto-optical microstructure composed of InSb and metasurface with a dielectric interlayer. In the Voigt magnetic field configuration, the reflectance of the p-polarization waves obliquely impinging on the InSb wafer exhibits high nonreciprocity, while the reflectance of the s-polarized wave is reciprocal. Based on the unique magneto-plasmonic modes on the InSb surface, the nonreciprocal reflection in this device can be enhanced by using the destructive interference between the direct reflection and the multiple reflections in the resonance cavity between the InSb and metasurface. After the optimization, the isolation power of the device exceeds 55 dB with the insertion loss of only −3.92 dB under a very weak magnetic field of 0.2 T at room temperature. More importantly, the introduction of the metasurface can reduce the operating frequency of the isolator from 2.434 to 2.136 THz. This low-loss, weak magnetic field, room temperature operating, and high isolation THz isolator shows its broad potential in THz application systems.

太赫兹隔离器在由InSb和具有介电夹层的超表面组成的磁光微结构中实现了太赫兹不可逆反射。在Voigt磁场配置中，p倾斜入射在InSb晶片上的偏振波表现出很高的不可逆性，而 s-极化波是互易的。基于InSb表面上独特的磁等离子体模式，可以通过使用InSb和超表面之间的共振腔中的直接反射和多次反射之间的相消干涉来增强此设备中的不可逆反射。经过优化后，在室温下0.2 T的极弱磁场下，器件的隔离功率超过55 dB，插入损耗仅为−3.92 dB。更重要的是，引入超颖表面可以将隔离器的工作频率从2.434 THz降低到2.136 THz。这种低损耗，弱磁场，室温工作和高隔离度的THz隔离器显示了其在THz应用系统中的广阔潜力。