Influence of anisotropy of a superconductor on electromagnetic wave reflection

The reflection of electromagnetic waves (EMW) at the surface of an anisotropic superconductor is investigated. Parameters of the reflected wave are expressed in terms the components of the surface impedance tensor. It is shown that anisotropy of the superconductor leads to two effects. First, a linearly polarized wave has in general an elliptic polarization after reflection. Second, the polarization ellipse of the reflected wave is turned relative to the EMW plane of incidence. The strength of these effects is determined by the ratio of the London penetration depth λ to the incident EMW length λw. It is found that the effect of anisotropy in the microwave region (λ/λw≪1) is virtually absent. The observed effects become noticeable only in the optical range (λ/λw≃1). In the case when the polarization plane of the incident EMW is parallel to the anisotropy axis, the polarization of the reflected EMW remains unchanged.