| An optical isolator is an optical component that allows unidirectional light propagation. The monolithic integration of optical isolators is not sufficiently obtained yet. The commercial optical isolators are bulk isolators. However, the bulk isolators are not efficient enough in integrated photonics as a consequence of including polarizer and rotator which are hard to integrate. On the other hand, reflected light can be blocked with a proper design of waveguide using nonreciprocal phase shift or nonreciprocal loss concepts. These are the results of different effective refractive indices for opposite directions of light propagation. In this study, how the direction of magnetic field affects the effective refractive index in waveguides containing ferromagnetic layer was demonstrated using Maxwell's equations and required boundary conditions. Also, the light propagation in bulk media under the influence of external magnetic field for different configurations of magnetic field was examined to compare the results with the ones obtained using waveguide containing ferromagnetic layer. The advantage of waveguide structure was found as existing of longitudinal component of electric field. Different effective refractive indices were calculated for opposite directions of light propagation. |
