KRYSHENIK V. Stimulated anosotropy and relaxation effects in amorphous chalcogenides

The thesis is dedicated to the study of optically anisotropic properties and relaxation transformations at physical aging and under the influence of external factors in the thermally deposited amorphous films of As-S(Se) systems, the possibilities of their usage in opto-electronic and integrated -optical devises have been considered. The main results of experiments have been obtained by using resonant excitation of optical modes in the film structure. Natural and photo-stimulated optical anisotropy (birefringence) found in as-deposited films have been studied. For As-S films maximal values of natural birefringence have been found in the vicinity of As2S5 compositions, whereas for photo-induced birefringence a monotonous rise in the anisotropy parameter with increasing As content. Based on the analysis of the results obtained the models which explain the probable nature of these phenomena have been proposed. They take into account the character of organization of the film medium structure and its changes at local levels. Relaxation changes of optical parameters of the films have been investigated. interpolation relaxation dependencies of the changes in the parameters which confirm the activation, structurally conditioned character of transformations have been calculated. The possibility of producing opto-electronic and integrated-optical devices with passive and active operating functions of basic elements with amorphous chalcogenides applications has been shown.