Bashchenko S. Research of interaction of created ecximer laser complex UV radiation with sapphire and porous silicon.

The thesis is devoted to creation of excimer laser complex having super-high spectral brightness of radiation, capability of generated line thin tuning as well as studying its radiation effect on XeCl* laser active media, sapphire and porous silicon. For the first time, influence of size and position of an additional intrinsic photon field ("the photon boiler") in the resonator of excimer XeCl* laser on power and spatial characteristics of its radiation are detected and studied experimentally. Interpretation of phenomena based on ions chlorine photo-ionization near cathode is suggested, too. By results of these investigations, offered are advanced modifications for the most used in excimer lasers plane-parallel and unstable telescopic resonators. These modifications increase: radiation energy, its density in beam cross-section, symmetry and directivity of the beam. The mechanisms of sound pfoto-generation in sapphire under varied laser irradiation are investigated, too. For the first time, formation, e xistence and depletion of particular surface layer on sapphire under excimer ArF* laser irradiation in a plasma mode interaction are detected experimentally. The conditions of interaction of an ArF* excimer laser radiation with sapphire for ablative and plasma modes of interaction as well as for mutual transitions between them are determined. For the first time, the effect of laser UV irradiation of porous silicon surface with a composite morphology on its fundamental characteristics: spectral distribution and temperature dependence of integral intensity for its photoluminescence red-orange band, is revealed. Also shown are the high sensitivity of the photoacoustic method and its suitability for determining threshold of sapphire laser destruction as well as control of a degree of porous silicon surface cleaning after etching.