Terahertz isolator in metal plate waveguide

Abstract

In this work, we present a terahertz (THz) isolator in metal parallel plate waveguide (PPWG). A magneto-optical film with 30um thickness is coated on one side of the metal plate of PPWG with 100um width, forming a metal-magnetoair-metal hybrid waveguide. Due to the non-reciprocity of magneto-optical medium and the asymmetry of the waveguide structure, this waveguide show a strong one-way transmission property. The numerical simulation shows that this THz isolator has a maximum isolation of 30dB and a 20dB operating bandwidth of 90GHz under a magnetic field of 0.3T, and its insertion loss is smaller than 0.5dB. Moreover, this operating frequency band can be widely tuned by changing the external magnetic field and temperature. This low-loss, high isolation, broadband tunable nonreciprocal THz waveguide has a great potential for THz application systems.