NEAR-FIELD THEORETICAL-STUDY OF A MAGNETOOPTICAL GRATING

We propose a theoretical description of a near-field observation of a magneto-optical grating. We consider a scanning tunnelling optical mic roscopy (STOM) experiment where the sample is a thin isotropic magneti c material. We choose a transverse geometry: the magnetization is perp endicular to the plane of incidence and parallel to the grating groove s. For calculating the detected signal we use a perturbative diffracti on theory of a multilayer anisotropic structure. The formalism has bee n tested by modelling a far-field diffraction experiment. Then we calc ulate STOM near-field signal above the grating and compare optical ima ges and magneto-optical images.