Isotropic-uniaxial crystal interfaces: Negative refraction and backward wave phenomena

We analyse the conditions necessary for negative refraction and backward wave phenomena to be produced on real dielectric non-magnetic isotropic-uniaxial crystal interfaces. The analyses are based on the geometric description of the extraordinary ray and its relationship with the extraordinary wave number vector. We also make an analytical study of the wave number and the time-averaged Poynting vectors under these conditions. We show that the proposed vectorial method allows making the calculi for both phenomena for every orientation of the optical axis with regard to the plane of incidence and, consequently, it could be applied in order to examine these effects and their consequences.