We present an original magneto-optical Scanning Near-field-Optical Microsco
pe (SNOM) configuration,, using an apertureless probe, and devoted to the c
haracterization in transmission of magnetic samples. Our experimental devic
e provides simultaneously the near and far field optical images, in Magneto
-optical Circular Dichroism mode (MCD): and the sample surface topography.
The preliminary near field images of an iron garnet test-sample reveal surf
ace modifications in the magnetic domain distribution, unresolved in the fa
r field image, and unrelated to the topographic features. The near field im
age resolution reaches 240 nm, corresponding to the theoretically estimated
size of the smallest magnetic structures.