Tunable polar magneto-optical Kerr rotation of light from a one-dimensional photonic crystal containing a Graphene/InAs slab at THz range

Abstract

Magneto-optical effects of graphene and InAs layers generated by gyrotropic behaviors under an external magnetic field, make them desirable for magneto-optical applications. In this paper, the polar magneto-optical Kerr effect of reflected light from a one-dimensional photonic crystal containing a magneto-optical slab (a graphene sheet on an InAs layer) has been investigated in the THz frequency region. The intensity reflection coefficient and Kerr rotation angle spectra of the reflected light from the structure have been calculated using the developed 4 × 4 transfer matrix method. By adjusting the thickness of the InAs layer in the structure, a narrow deep mode inside the photonic bandgap appears. The results revealed that the corresponding enhanced Kerr rotation angle occurred at the deep mode frequency. The performance of the structure in the presence and absence of the graphene sheet is investigated considering the FOM behaviors. The tunability and enhancement of the Kerr rotation angle are investigated by varying the external magnetic field strength and the charge career density of graphene. Finally, the polarization state of reflected light at the deep mode frequency is visualized. The results of this work may have potential applications in designing magnetic field sensors and tunable Kerr-rotation-based devices.