摘要
We introduce a nanoplasmonic isolator that consists of a cylindrical resonator placed close to a metal-dielectric-metal(MDM) waveguide. The material filling the waveguide and resonator is a magneto-optical(MO) material, and the structure is under an externally applied static magnetic field. We theoretically investigate the properties of the structure and show that the cavity mode without MO activity splits into two modes when the MO activity is present. In addition, we find that the presence of the MDM waveguide leads to a second resonance due to the geometrical asymmetry caused by the existence of the waveguide. We also show that, when MO activity is present, the cavity becomes a traveling wave resonator. Thus, the transmission of the structure depends on the direction of the incident light, and the proposed structure operates as an optical isolator.
