Threshold field for nonlinear power absorption in Mg doped LiNbO3 crystals

Abstract

On the basis of semi-classical approach, we have developed a theoretical model to understand the mechanism of optical damage threshold in congruently grown Mg doped LiNbO3 crystals. We consider the phonon mode excitation in the crystal produces standing waves. The mode of vibration is derived quantum mechanically and further related it with the polarization of the crystal. The power absorbed during the process results in the change of energy states. The balance of energy state equation is defined with the help of relaxation time and we obtain a formula for the magnitude of field at which the nonlinear power absorption by phonon mode occurs in the crystal. The nonlinear absorption of power causes optical damage in the crystal. We plot a graph for energy absorption by phonon modes as a function of applied field.On the basis of semi-classical approach, we have developed a theoretical model to understand the mechanism of optical damage threshold in congruently grown Mg doped LiNbO3 crystals. We consider the phonon mode excitation in the crystal produces standing waves. The mode of vibration is derived quantum mechanically and further related it with the polarization of the crystal. The power absorbed during the process results in the change of energy states. The balance of energy state equation is defined with the help of relaxation time and we obtain a formula for the magnitude of field at which the nonlinear power absorption by phonon mode occurs in the crystal. The nonlinear absorption of power causes optical damage in the crystal. We plot a graph for energy absorption by phonon modes as a function of applied field.