Abstract:  Asymmetric Transport (AT) is one of the key concepts in the conversion between polarization states of light. Achieving tunable AT effects is a crucial technology for constructing multifunctional information multiplexing photonic integrated diodes. However, the current undergraduate-level optics textbooks have little introduction of this content, which makes it more difficult for students to understand and master in the learning process . Therefore, as an extended teaching case, this paper designs an F-shaped monolayer graphene nanoribbon array structure and numerically simulates its AT effect using COMSOL Multiphysics software based on the Finite Element Method (FEM). It was found that under the excitation of Right Circularly Polarized (RCP) and Left Circularly Polarized (LCP) light, the structure exhibits Bonding and Anti-Bonding resonance modes, which give rise to the AT effect. The influence of parameters such as the arm length of the F-shaped monolayer graphene nanoribbon structure and the Fermi energy level of graphene on the AT effect was analyzed. It was observed that as the middle arm length p of the structure increases, the resonance peak near 13.6 μm undergoes a redshift, while the resonance peak near 11.4 μm remains stationary. Additionally, as the Fermi energy level of graphene increases, both resonance peaks exhibit a blueshift, enabling precise frequency selection and sensing of the AT signal. These results provide a basis for designing and optimizing graphene nanostructures for generating and modulating AT effects.

Key words: graphene, surface plasmon polaritons, asymmetric transmission