Minailova I. Linear phase anisotropy induced of thermoelasticity in a solid in the reproduction of modulation polarimetry

This dissertation is dedicated to dimensional distribution of the temperature values and mechanical stress using transparent homogeneous samples. The functional connection between temperature and mechanical stress was experimentally established. By means of heat flow from the contact heating of the sample or irradiation in condition of thermal independence of all coefficients that had been involved in the generation of thermal stresses and their registration, thermoelastic state was induced. Thermostress was detected by means of modulation polarimetry. The functional link between dimensional distribution of the temperature values and mechanical stress in the form of Poisson equation was established. Using polarization modulation of the sample in time and space mechanical stresses induced by inhomogeneous thermal flow from external heat source were investigated experimentally. The fact of coordinate dependence of the temperature at different times T(y), T(t) during the steady state of deformation was obtained by graphical integration of mechanical stresses. This transformation is the solution of the inverse problem of thermoelasticity. Time coordinates of the extreme in the kinetics of stress in conjunction with the spatial coordinate observations allow us to determine the velocity (dynamics) of the thermal front. Relaxation characteristics of stress are with high precision approximated by exponential functions, and this is a consequence of the substance coefficients' independence from the temperature. The high reproducibility of the measurement results at repeated thermal cycles indicates the absence of structural changes in the sample. The qualitative correspondence of the experimental results to mathematical models was established. Superposition of the two-beam and multiple-beam interference of polarized rays in condition of thermoelasticity inside a silicon crystal induced by inhomogeneous temperature flow from the contact heating was detected. Due to this, it is possible to determine a series of thermal and elastic constants of the material with high accuracy and definition.