KENBIKYO Vol.52▶No.3 2017
■Feature Articles: Recent Topics of Magnetic Imaging

Development of Kerr Effect Microscope with Detection of Local Magnetization Direction and Its Application to Spatial Magnetic Field Detection

Sakae Meguro and Shin Saito

Abstract: Kerr effect microscope based on the photographic method is a device for observing the magnetic domain of a magnetic material by converting a polarization change caused by the magneto-optical Kerr effect. This method is widely utilized because of its features, such as non-contact and non-invasive observation, extensibility of applying a high magnetic field, capability of analyzing dynamical magnetization process, versatility for a wide range of magnetic domain size. The improvements of the performance of the Kerr effect microscope have been quested, mainly based on how to detect minor change in spatial and temporal polarization with high resolution and contrast. In addition, since high-quality magnetic domain images can be acquired owing to the high performance, specific efforts to detect not only magnetic domains but also three-dimensional detection of the local magnetization direction in the magnetic domains have also been performed. In this report, after outline descriptions of these observations techniques, the observation of the centimeter order magnetic domain by the reduced optical system which is the application of the microscope magnified optical technique will be introduced. Furthermore, the attempt of imaging the spatial magnetic field by using the magneto-optical effect of the magnetic transfer film will be reported.

Key words: magneto-optical Kerr effect, magnetic domain observation, detection of the local magnetization direction, prober, imaging of the spatial magnetic field