DICHROIC IMAGING OF MAGNETIC DOMAINS WITH A SCANNING NEAR-FIELD OPTICAL MICROSCOPE

Scanning near-field optical microscopy (SNOM) has been used to study o ptical circular dichroism of a sputtered Co/Pt multilayer on glass sub strate. The dichroic imaging consistently reveals magnetic domains of subwavelength scale. By applying in-situ a perpendicular magnetic fiel d, we have imaged the development of the domains as a function of fiel d treatment. The proposed SNOM also has the capability to image the sa mple topography by simultaneous scanning tunneling microscopy (STM) me asurements, which allows us to discriminate between the magneto-optica l contrast and other dichroic signals.