DIRECT OBSERVATION OF SURFACE-PLASMONS IN YBCO BY ATTENUATED TOTAL-REFLECTION OF LIGHT IN THE INFRARED

Surface plasmons have been observed directly in YBCO films in an Otto-geometry attenuated total reflection measurement at a wavelength of 3.392 mum. The laser deposited films are c-axis oriented on an MgO substrate. This observation confirms theoretical deductions from complex dielectric function data. Measured data have been fitted to a theoretical model and are compared with the optical constants determined by Bozovic [1]. The investigations have been extended to films with other orientations to investigate whether material anisotropy is reflected in the results and non-metallic behaviour is found.