Non-magnetic continuum quasi bound terahertz non-reciprocal device

Abstract

The terahertz isolator breaks the Lorentz reciprocity and is a typical non-reciprocal unidirectional transmission device, which is an indispensable and important component in terahertz systems. Due to the loss of terahertz radiation in current non-reciprocal materials, terahertz non-reciprocal devices remain a significant challenge. By combining third-order nonlinearity with the out of plane asymmetry and in-plane breaking of device structures, a nonlinear silicon grating metasurface terahertz isolator is proposed. By controlling the quasi-bound state radiation linewidth of the continuum medium, the designed silicon grating metasurface structure has an isolation of 12.08 dB and an insertion loss of 4.7 dB under terahertz intensity of 0.5 MW/cm². This device provides a new solution for the design of terahertz non-reciprocal devices and has great application prospects in terahertz integrated systems.