Selective sensitivity in Kerr microscopy

I V Soldatov; R Schäfer

doi:10.1063/1.4991820

Selective sensitivity in Kerr microscopy

Rev Sci Instrum. 2017 Jul;88(7):073701. doi: 10.1063/1.4991820.

Authors

I V Soldatov¹, R Schäfer²

Affiliations

¹ Institute for Metallic Materials, Leibniz Institute for Solid State and Materials Research (IFW) Dresden, Helmholtzstrasse 20, D-01069 Dresden, Germany and Institute of Natural Sciences, Ural Federal University, 620002 Ekaterinburg, Russia.
² Institute for Metallic Materials, Leibniz Institute for Solid State and Materials Research (IFW) Dresden, Helmholtzstrasse 20, D-01069 Dresden, Germany and Institute for Materials Science, TU Dresden, 01062 Dresden, Germany.

PMID: 28764508
DOI: 10.1063/1.4991820

Abstract

A new technique for contrast separation in wide-field magneto-optical Kerr microscopy is introduced. Utilizing the light from eight light emitting diodes, guided to the microscope by glass fibers and being switched synchronously with the camera exposure, domain images with orthogonal in-plane sensitivity can be displayed simultaneously at real-time, and images with pure in-plane or polar contrast can be obtained. The benefit of this new method of contrast separation is demonstrated for Permalloy films, a NdFeB sinter magnet, and a cobalt crystal. Moreover, the new technique is shown to strongly enhance the sensitivity of Kerr microscopy by eliminating parasitic contrast contributions occurring in conventional setups. A doubling of the in-plane domain contrast and a sensitivity to Kerr rotations as low as 0.6 mdeg is demonstrated.