Experimental study of visible reflection variation from high-temperature superconductor ceramics as a result of irradiation by excimer lasers

The present study started on the basis of a suggestion concerning possible structural modification of HT SC by means of laser irradiation with a frequency close to or in resonance with vibrational or electronic bonds of lattice. The research started in P. N. Lebedev Physical Institute in the frame of the program of IR-laser irradiation of HT SC using an unic 16 - 18 micrometers ED GDL CO2 laser, developed in this institute. An investigation of UV wavelengths effect on these ceramics was fulfilled with use of the high power excimer lasers facility of Marseille IMFM New Lasers Group. We report here on preliminary experiments related to reflectivity change of polarized He-Ne laser beam at Brewster angle in the cases of super conducting and non-super conducting ceramic oxides following excitation by ArF (193 nm) and XeCl (308 nm) excimer lasers for conditions below the ablation threshold.