(a) A binary mask in a Pt thin foil generated by ion beam under computer control design, exhibiting a dislocation type geometry, and its diffraction pattern exhibiting two satellite vortex spots carrying opposite l = 1 and l = -1 OAM; (b) EELS spectra of the L₃ and L₂ lines in a Fe thin foil, recorded with the right and left satellite vortex spots. Their difference in intensity shows the magnetic circular dichroism of the specimen homogeneously magnetized by the magnetic field of the objective lens (from Verbeeck et al. [196].)