Optical properties of a nearly ferroelectric superconductor

Optical properties of a nearly ferroelectric superconductor in the dielectric response are theoretically investigated based on the electrodynamics of the nearly ferroelectric superconductors. The optical reflectance and transmittance of TE and TM waves are calculated and analyzed for two model structures, a superconductor occupying the half-space and a superconducting film of finite thickness. At the oblique incidence to a free-space-superconductor interface, it is found that the Brewster angle of a TM wave is close to the grazing angle of incidence. In the transmittance spectrum for a superconducting film, a sharp comblike distribution of the resonance peaks is found. These peaks are not regularly spaced in the frequency domain. The number of peaks increases substantially with an increase in the thickness of the film. In addition, the effect of the oblique incidence on this anomalous comblike distribution in a TM wave is stronger than that of a TE wave.