Magneto-optic Kerr effect CCD imaging with polarization modulation technique

Abstract

We have developed a magneto-optic Kerr effect (MOKE) imaging system with a charge-coupled-device (CCD) camera by using the rotating compensator technique. We chose optimal conditions of the rotation frequency of the compensator with stable rotation along with a CCD camera frame rate that allowed precise control of the exposure timing in order to link with the angle of the compensator. Precise timing management of the CCD exposure enables us to carry out repeated experiments, which greatly improves the signal-to-noise ratio of the longitudinal MOKE signal. We applied the technique to the material characterization of the Ni81 Fe19 thin film and its microstructure, and succeeded in evaluating the spatial variation of the complex magneto-optic constant Q of the sample. Because of its attractive advantages such as high-speed and compactness, the present method provides a novel platform for investigating the domain structures in various magnetic materials.

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

“…Yet, TMOKE has an important feature, namely it is determined by the magnetic properties of the interface and sample geometry and therefore can be used for the control of light at the nanoscale. Recent advances in nanotechnology allow one to synthesize magnetic nanostructures where the magnitude of TMOKE is significantly increased in the vicinity of optical resonances [20][21][22][23][24][25]. In particular, TMOKE enhancement has been demonstrated in magnetoplasmonic crystals [26][27][28][29][30][31][32][33] and magnetoplasmonic nanoantennas [34][35][36][37] where plasmonic resonances come into play.…”