Dielectric crystal coupled with guided-mode resonance to enhance the magneto-optical Kerr effect and sensing behavior in transmission mode

Abstract

In this study, we introduce a high-performance magneto-optical sensor that features enhanced amplitude and sensitivity, achieved through guided-mode resonance (GMR) excitations in an aluminum antimonide slab. This advancement is facilitated by a square, periodically arranged nanorod structure comprising dielectric materials. The electromagnetic field distributions were obtained along with the transmission spectra to elucidate the GMR mode in our proposed structure, thereby highlighting the enhancement of the transverse magneto-optical Kerr effect (TMOKE) signal in the transmitted mode and the corresponding sensing performance. The findings demonstrate that the position of the TMOKE resonance is remarkably responsive to variations in the background refractive index, yielding an impressive sensitivity of 188.7° per refractive index unit, coupled with a narrow linewidth owing to the inherent low loss of dielectric materials. This investigation lays the groundwork for novel advancements in linear optics, integrated optical circuits, and low-loss biosensing applications.