Enhancement of the Faraday Effect and Magneto-optical Figure of Merit in All-Dielectric Metasurfaces

All-dielectric metasurfaces are promising candidates for the next-generation planar photonic devices. Magneto-optical (MO) all-dielectric metasurfaces are particularly attractive due to their enhanced MO response at the subwavelength scale. In this paper, we report a MO all-dielectric metasurface based on a Ce:YIG thin film and a two-dimensional array of the silicon nanoresonators. Compared to a bare Ce:YIG film, the device shows a four times enhancement of the Faraday effect and the MO figure of merit (FOM) at 1370 nm wavelength. The high Faraday rotation (FR) and FOM are caused by the increase in the interaction time between light and magnetic matter which is indicated by the local field increase inside the Ce:YIG film when exciting the hybrid Mie resonance-waveguide modes. Simultaneously enhanced FR and FOM make the dielectric MO metasurfaces promising candidates for free-space MO devices such as MO sensors, MO modulators, and nonreciprocal photonic devices.