In our group we are studying various exotic interactions of fields, produced in the focus of femtosecond laser pulse, with atoms, molecules, solids and plasmas (1 femtosecond = 10-15 sec⁡). To support our studies, we are developing ultrashort radiation sources covering a wide range of the spectrum from soft X-ray (high harmonic generation -HHG) to infrared femtosecond lasers.