Significant enhancement of magneto-optical effect in one-dimensional photonic crystals with a magnetized epsilon-near-zero defect.

Optical nonreciprocal transmission possesses a broad range of applications such as optical isolation, all-optical signal processing, and integrated photonic circuits. The main underlying mechanism is that a static magnetic field can break the time-reversal symmetry in the presence of magneto-optical materials. However, the typical devices usually need a large size because the magneto-optical activity of materials is weak. In this paper, we realize strong nonreciprocal transmission in a one-dimensional photonic crystal with a magnetized epsilon-near-zero defect. The inherent weak magneto-optical activity is significantly enhanced in the magnetized epsilon-near-zero defect because of the field intensity enhancement mechanism. Our results show that the wavelength shift of transmission peaks along two opposite incident directions can be up to 100 times higher than that in the case of a bismuth-iron-garnet defect. These results provide a new perspective to design novel magneto-optical devices with a small size and open novel routes to exploit advanced materials for steering the electromagnetic waves in nano-scale structures. [ABSTRACT FROM AUTHOR]