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Extended depth-of-field magneto-optical Kerr microscopy for applications in three-dimensional nanomagnetism

Le Zhao1,*, Alexander Rabensteiner1, Miguel Ángel Cascales-Sandoval1, Naëmi Leo1,2, Sabri Koraltan1, and Amalio Fernández-Pacheco1,†

  • *Contact author: le.zhao@tuwien.ac.at
  • †Contact author: amalio.fernandez-pacheco@tuwien.ac.at
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Phys. Rev. Applied 26, 034044 – Published 21 September, 2026

DOI: https://doi.org/10.1103/jb45-29sy

Abstract

High-resolution imaging of magnetic nanostructures is essential for understanding fundamental spin phenomena and designing advanced devices. Recent developments in three-dimensional (3D) nanomagnetism have highlighted the growing need for imaging techniques that can capture magnetic structures across curved or tilted surfaces with high sensitivity. Though widely used as a powerful technique for imaging magnetization states, conventional magneto-optical Kerr effect (MOKE) microscopy faces inherent limitations in measuring nonplanar systems due to its shallow depth of field (DOF). Here, we present an extended depth-of-field MOKE imaging approach, combining through-focus scanning with image-stitching-based reconstruction, to obtain sharp and well-resolved magnetic domain images across nonplanar sample geometries. The method is validated on both perpendicularly and in-plane magnetized films tilted on purpose for this study, enabling quantitative analysis of domain morphology and detection sensitivity. This laboratory-accessible technique provides a fast and versatile route for 3D magnetic imaging, complementing large-scale x-ray-based methods and offering a practical tool for investigating nonplanar magnetic samples with tilted or curved 3D geometries.

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Phys. Rev. Applied 26, 034044– Published 21 September, 2026
  • Received 15 January 2026
  • Revised 27 April 2026
  • Accepted 15 June 2026
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