Transverse Magneto-Optical Kerr Effect in Magnetite Covered by Array of Gold Nanostripes

Abstract

We study theoretically and experimentally a magneto-optical Kerr effect (TMOKE) in magnetite film covered by sub-wavelength grating consisting of gold nanostripes. Our rigorous coupled wave analysis (RCWA) simulations of optical reflection and transmission coefficients of the structure under study predict a multiple enhancement of TMOKE response in transmission as compared with a plain magnetite film without gold nanostripes. We demonstrate that due to the high absorption losses in magnetite film, the quality factors of the optical resonances in our sample are low which results in wide areas on the dispersion diagram where the TMOKE can be observed.