Wide-band enhancement of the transverse magneto-optical Kerr effect in magnetite-based plasmonic crystals

Abstract

The transverse magneto-optical Kerr effect (TMOKE) in magnetite-based magneto-plasmonic crystals is studied experimentally and theoretically. We analyse angle-resolved TMOKE spectra from two types of structures where noble metallic stripes are incorporated inside a thin magnetite film or located on top of a homogeneous film. A multiple wide band enhancement of the TMOKE signal in transmission is demonstrated. The complex dielectric permittivity and gyration are experimentally determined using the ellipsometry technique as well as Faraday rotation and ellipticity measurements. The obtained parameters are used in rigorous coupled wave analysis (RCWA) calculations for studying the optical resonances. Our RCWA calculations of transmittance and TMOKE are in good agreement with the experimental data. The role of guiding and plasmonic modes in the TMOKE enhancement is revealed. We demonstrate that the TMOKE provides rich information about the studied optical resonances.

Magnetically controllable metasurface and its application

“…Besides, the MO effect enhancement of 1D grating [61][62][63][64], and 2D nanoarray of different shapes [65,66] in similar physical mechanisms was also reported. In addition to the above mentioned metal/dielectric double-layer structure, the metal/dielectric/metal structure, such as Ag/ Bi:YIG/Ag, could also realize the MO effect enhancement, and an asymmetric Fano resonance was found in the reflection spectrum of TMOKE signal [67].…”

Theoretical Study on Metasurfaces for Transverse Magneto-Optical Kerr Effect Enhancement of Ultra-Thin Magnetic Dielectric Films

“…It is well known that plasmonic resonances are able to enhance TMOKE response in magneto-plasmonic crystals [23][24][25]. Very recently, the enhanced TMOKE signal was also observed for plasmonic metal covered thick magnetic films with a thickness larger than 100 nm [26,27]. However, it is still challenging to obtain giant TMOKE enhancement in magnetic dielectric films with a thickness smaller than 50 nm.…”

Magneto-optics of the 2D iron-garnet nanocylinder array with localized and lattice modes

“…One of the straightforward ways to enhance the magneto-optical Faraday rotation in thin films is utilization of the photonic crystals with microcavity (defect) magnetic layers. 7, [17][18][19][20][21][22][23][24][25][26] Photonic crystals surrounding a magnetic layer act as a Bragg mirrors leading to the multiple re-reflection of light inside the magnetic layer like in the Fabry-Pérot cavity. Faraday polarization rotation constantly increases each loop the light travels inside the magnetic layer.…”