Jiri Stepan finished in 2004 his Master studies at the Faculty of Mathematics and Physics of Charles University in Prague (Czech Republic). In 2008 he obtained his PhD degree at the Paris Observatory, after having carried out his thesis under the double supervison of Prof. Petr Heinzel (Astronomical Institute of the Czech Academy of Sciences) and Dr. Sylvie Sahal Brechot (Paris Observatory, France). The PhD research topic was the transfer of spectral line polarization in solar flares, taking into account impact polarization. Soon after his thesis he joined the research group of Prof. Javier Trujillo Bueno, where he worked till 2011. His scientific interests during this post-doctoral period at the IAC were the development of massively parallel codes for solving the 3D radiative transfer problem of scattering line polarization and the Hanle effect (e.g., the PORTA code), and applications aimed at modeling high-sensitivity spectro-polarimetric observations of chromospheric lines. Jiri Stepan is presently a scientific staff member of the Academy of Sciences of Czech Republic. He is a team member of both the Chromospheric Ly-Alpha SpectroPolarimeter (CLASP-1) and the Chromospheric Layer SpectroPolarimeter (CLASP-2) sounding rocket experiments. As member of the POLMAG research group, he is contributing to the development of WP-4, WP-5 and WP-6.