Prototype of Atomic Force Cantilevered SNOM Based on Through-The-Lens-Type Optical Lever and Polarized Illumination and Detection System

Atomic force cantilevered scanning near-field optical microscopy (ANOM) has been proposed for observing a micromagnetic structure of a recorded magneto-optical (MO) disc. The prototype system has an ability to obtain both atomic force microscopy (AFM) and scanning near-field microscopy (SNOM) images simultaneously. This system has some special functions: (1) it keeps the sample-probe gap constant with atomic force and an AFM cantilever, (2) it generates near-field light from the small aperture formed on the tip of the cantilever, (3) it uses a polarized light in the laser beam illumination and detection systems, and (4) it adjusts laser beams incident on fixed positions of the cantilever in ANOM optics. As an experimental result, we obtained SNOM and contact mode AFM images of a commercial MO disc. We can detect a polarized plane at a minimum angle of less than 0.2 deg. and observe submicron recorded magnetic domains on a 640 MB MO disc.