Nonlinear interaction of moving space-charge and photoconductivity gratings in Bi12SiO20 crystal

摘要

A nonlinear interaction of moving space-charge and photoconductivity gratings is experimentally investigated. In the presence of a dc electric field, a crystal is irradiated with an oscillating interference pattern with a spatial frequency K and an oscillation frequency omega. An ac electric field with a frequency Omega is also applied to the sample. At certain frequencies omega and Omega , the crystal exhibits two types of interacting oscillations: the space-charge grating moving with velocity omega - Omega/K and the photoconductivity grating moving with velocity -omega/K. The effect is studied using the method of the nonstationary photoelectromotive force in a photorefractive Bi12SiO20 crystal. (C) 2004 MAIK "Nauka / Interperiodica".