G. Carelli et al., OPTICAL-PROPERTIES OF YBACUO THIN-FILMS AT FAR-INFRARED MONOCHROMATICLIGHT, International journal of infrared and millimeter waves, 16(7), 1995, pp. 1189-1199
By using monochromatic sources of radiation we measured the reflectivi
ty and transmission vs temperature behavior of YBaCuO thin film in the
Far Infrared region in the range 300-20 K. A smooth change of optical
properties is observed from critical temperature down to 40 K with an
evident reduction of the losses for all the frequencies we examined.
To analyze the use of YBaCuO films as semireflecting elements in submi
llimeter devices we made a preliminary study of the optical properties
of the substrate in the same conditions. The permanence of the sample
in a superconducting phase can be deduced from its room-temperature t
ransmittance, as it changes drastically if some degeneracy occurs in t
he film.