Mueller matrix optical and magneto-optical characterization of Bi-substituted gadolinium iron garnet for application in magnetoplasmonic structures

L. Halagačka, K. Postava, M. Vanwolleghem, F. Vaurette, J. Ben Youssef, B. Dagens, J. Pištora
2014 Optical Materials Express  
A ferromagnetic garnet, used as a magneto-optical (MO) material in magneto-photonic and magneto-plasmonic structures, is characterized. We present a general procedure to determine optical and magneto-optical functions of the magneto-optic garnet by using Mueller matrix ellipsometry. In the first step, the optical functions (the refractive index spectra) of the (CaMgZr)-doped gallium-gadolinium garnet (sGGG) substrate and the Bi-substituted gadolinium iron garnet Gd 1.24 Pr 0.48 Bi 1.01 Lu 0.27
more » ... e 4.38 Al 0.6 O 12 (Bi:GIG) are obtained in the spectral range from 0.73 eV to 6.42 eV (wavelength range 193 nm -1.7 μm). Subsequently, the spectra of the magneto-optical tensor components are obtained by applying an external in-plane magnetic field in longitudinal and transverse geometry. The obtained functions are then used to fit the Mueller matrix spectra of a magneto-plasmonic structure with a gold grating on the magneto-optic garnet layer. This structure has recently been demonstrated to have strongly enhanced transverse magneto-optic Kerr response at visible and near-infrared frequencies. By taking possible fabrication imperfections (surface roughness, residual photo-resist layer, thickness deviation) into account, the measured strongly enhanced MO response fits very well to the numerical model predicting these exaltations. OCIS codes: (250.5403) Magneto-optic systems; (160.3820) Magneto-optical materials; (120.2130) Ellipsometry and polarimetry.
doi:10.1364/ome.4.001903 fatcat:2wmew7u4crdcli3fnqj2ykeece