Review of terahertz nonreciprocal devices based on gyrotropic material InSb

Abstract

As the developing of the Terahertz (THz) optics, the THz functional devices is highly desired. However, most conventional materials and devices are limited with the efficiency, bandwidth and tunability. Thus, the THz magneto-optical (MO) materials play an important role in the THz systems due to its unique gyrotropic material properties and the magnetic tunability. Here, we review the magneto-optical materials, especially the unique gyrotropic semiconductor |InSb, in THz band. Based on these MO materials, MO devices are introduced, including magneto-metasurfaces, magneto-plasmonics and magnetic photonic crystals. On the basis of the unique properties of InSb, we proposed several nonreciprocal THz devices. Due to the nonreciprocity and magneto-tunability, the acitve wavefront manipulation and nonreciprocal transmission are realized. These de- vices have strong potentials in morden terahertz application systems and provide effective way of designing terahertz functional devices.