Near-field magneto-optical microscopy in collection and illumination mode

We present a new design and the application of a near-field magneto-optical microscope, which combines the operation in the collection (PSTM) or illumination mode (NSOM) and the simultaneous application of an external magnetic field. Magnetic information is obtained via polarisation contrast showing the relative orientation of the magnetisation in magnetic thin films and microstructures due to the Faraday effect in transmission. Controlled by the shear-force technique the topography is recorded simultaneously with the magneto-optical signal. For the preparation of the aperture at the fibre tips a new, simple metal-coating technique is additionally introduced. For the first time near-field magneto-optical images obtained in the collection mode under static magnetic field conditions are presented. We have compared the illumination and collection mode with respect to near-field magneto-optical imaging of yttrium iron garnet films.