Direct Bloch line optical observation (invited)

A new technique for observing domain walls and lines in materials with perpendicular anisotropy is presented. It employs laser light in a laser scan microscope and uses anisotropic diffraction by the wall/line magnetic structure. The contrast obtained can be understood simply and a numerical computation shows good agreement with experimental results. Wall configurations with numerous lines may be obtained when nucleating parallel stripes upon reduction to zero of a saturating in-plane field.