Imaging of magnetic domain structures using optical techniques

Abstract

High-resolution optical techniques for the imaging of magnetic domains in ferromagnetic materials such as confocal microscopy and scanning near-field optical microscopy are discussed. The imaging capabilities of different techniques and image formation are investigated in the case of in-plane as well as out-of-plane magnetic anisotropy in different polarisation configurations. It is shown that the magneto-optical resolution of near-field measurements depends on the film thickness and is limited by the diffraction on magnetic domains throughout the film. For thin magnetic films, subwavelength resolution can be achieved. High-resolution optical imaging is required for characterisation of the micromagnetic and magneto-optical properties of novel magnetic materials in order to adopt a bottom-up approach in the search for new materials with improved characteristics.