Abstract
The aim of the project is to the study vortex dynamics by measuring far infrared radiation transmission of superconducting thin films in external magnetic field. On the principle of Mach-Zehnder interferometer we shall extend our experimental equipment for measuring the phase difference. From the obtained data it will be possible to determine complex conductivity in the terahertz frequency range. Comparison of the experimental data with various theory predictions will enable to test their validity and to get better understanding for the mechanism of the vortex motion. This represents an inevitable presumption for the development of new technologies, which will require to have the possibility to influence and control vortex motion.