Drage koleginice i kolege,

Active galactic nuclei (AGN), which contain supermassive black
holes (SMBH) at their centres, represent an extreme example of the
conversion of gravitational energy through mass accretion. Modern
studies employ various multi-wavelength observational techniques to
investigate the structure and physical processes of AGN. Polarimetry is
a powerful yet underutilized tool that can provide new insights into the
AGN's inner geometry and properties, but these observations are
challenging and, thus, rarely used. In this report, I am going to
introduce the key ideas of AGN polarimetry in optics highlighting the
physical processes and common tricks of data reduction. I briefly
discuss how different polarization signatures in the continuum and broad
emission lines relate to the mechanisms of polarization generation and
help to determine the parameters of the accretion disk, BLR and dusty
torus in AGN. Illustrating the physical mechanisms I will show the
recent observational results on AGN spectropolarimetry obtained at the
6m Russian telescope.