  In recent years several methods to overcome diffraction limit in the far
field microscopy have been demonstrated. Still the problem of superresolution
is reliably solved only for fluorescent microscopy, giving a resolution of up
to 20-30nm. Obtaining the optical resolution lower than 100nm without
fluorescent dyes requires using rather slow and complicated technique of
scanning near filed optical microscope (SNOM). We propose and demonstrate a
method of optical near field acquisition by far-field microscope through
observation of nanoparticles Brownian motion in immersion liquid. The
resolution of the method is restricted only by the size of nanoparticles that
can be registered (detected) by a given far field microscope. From this point
of view this resolution can achieve up to 10-20nm. Up to now we achieved a
resolution of about 140nm observing 120nm particles through an objective with
N.A.=0.4. The resolution is thus improved by factor of five for a given
microscope objective.
