Measurement of electrodynamic parameters of superconducting films in far-infrared and submillimeter frequency ranges

Abstract The possibilities of measuring the complex conductivity of thin superconducting films by using the far-infrared and submillimeter reflectivity and transmissivity techniques are discussed. It is shown, that within the framework of standard approaches a satisfactory accuracy is available only for the imaginary part of the conductivity. The data on the electrodynamic properties of superconducting NbN films at frequencies 3-25 cm −1 are presented.