Buryy O. The dynamics of the energy and mass transfer processes in activated YAG, YAP, LiNbO3 crystals and the quantum electronics devices based on them

The thesis is devoted to the clarification of regularities of the energy and mass transfer processes in the activated YAG, YAP, LiNbO3 crystals and to the determination of the possible ways of their optical properties modification as well as to the improvement of characteristics of the devices for generation, transformation and control of the coherent optical radiation based on these materials. Regularities of processes taking place in complex oxide crystals (YAP, YAP:Nd, YAP:Mn, YbAP, YAG:Cr,Mg, YAG:Yb, LiNbO3, LiNbO3:Mg, LiNbO3:Fe) during the thermo-chemical treatment are determined by means of the in-situ optical spectroscopy. Experimental kinetics of optical absorption changing are described by mathematical models taking into account the processes of diffusion and defects recharging. Parameters of these processes as well as their typical durations are determined. Mathematical models are developed and generalized for the most used types of the microchip lasers - cw and passively Q-switched ones. Optimization techniques are proposed using these models for lasers based on complex oxide crystals with the forth- and quasi-three-level generation schemes. Peculiarities of light passing throw the ferroelastic domain structure are analyzed. Using these results the mathematical models and the optimization techniques are developed for the devices based on the crystals (particularly, LiNbO3) that consist of ferroelastic domains - two-beam polarizing prisms and the terahertz generators. General method is proposed for optimization of the geometry of the acousto-, electro- and piezooptical interactions in the light beam control devices. It consists in the construction and analysis of the surfaces of the special 'extremal' type that represent all possible extrema of parameters characterizing values of the corresponding effects.