Abstract
The aim of this project is to study the optical properties of superconducting thin films by two independent methods – by a laser based terahertz magneto-spectroscopy in the laboratory FIRM and by a time domain spectroscopy in the laboratory for terahertz and ultrafast spectroscopy. By comparing the data coming from these two distinct experimental methods we will check the presence of possible nonlinearities which, in our opinion, could be responsible for problems with the theoretical interpretation of experimental data obtained until now. We shall find magnitude of the circular dichroism of the YBaCuO thin film in magnetic field.