Double electric dipole moment contribution model of the Verdet constant of paramagnetic magneto-optical materials

Besides considering the influence of the transition dipole moment, the impact of the external magnetic field and photoelectric field on the electron’s movement is also taken into account by using forced vibration to correct the electric dipole moment, and a unique double electric dipole moment contribution model of the Verdet constant of paramagnetic magneto-optic materials is deduced. Using terbium gallium garnet (TGG) crystal as an example, various microscopic effects and energy levels splitting inside the paramagnetic magneto-optic materials are analyzed in detail. Then, the Verdet constant of TGG crystal under different theoretical models is quantitatively solved. Compared with current theories, the results calculated using the double electric dipole moment contribution model are more consistent with the experimental data, indicating that the model has certain advantages. •Microscopic effects inside paramagnetic magneto-optical materials are analyzed and the mechanisms of Verdet constant are explained.•A double electric dipole moment contribution model of the Verdet constant is creatively constructed by considering the joint influence of the photoelectric field and external magnetic field on the motion of electrons.•The energy levels splitting of main ions in magneto-optical materials is analyzed by the quantum theory, and the Verdet constant is calculated quantitatively.