A new model for magneto-optical sensor based on geometrical parameters and refractive index

Abstract In this work, an all-dielectric magneto-optical refractometric sensor was designed using two methods: simulation analysis and modeling. In this structure, bismuth-substituted yttrium iron garnet (Bi: YIG), lithium niobate (LiNbO 3 ), and silicon oxide (SiO 2 ) are used to construct the grating, the middle layer, and the output part of the sensor, respectively. A magnetic field in the z-direction generates the transverse magneto-optical Kerr effect (TMOKE) signal to activate the structure. In addition, an optical field of 630 nm is applied to the structure. The model was created based on the geometrical parameters, the direction of the magnetic field, and the refractive index. The best-fit response was obtained by sweeping the period and refractive index of the analyte so that the output signals have an almost complete overlap with the response from the simulation. The change in refractive index leads to a shift of 0.4° in TMOKE, which is consistent with the simulation results. The time required for the analysis in the model by the system with CORE i7 (8 core) CPU and 32 GB RAM was a maximum of 30 s, while more than 1800 s were spent on the simulation.