ABSTRACT
A theory of photoinduced phase transitions for crystals with charge transfer complexes is proposed employing the mean field approximation. In the presented model, a unit cell is suggested to be in three states: neutral state, charge transfer state, and highly excited electronic state. The system can be transformed from neutral state to ionic one or vice versa through the excited level by an external electro-magnetic field. The system of kinetic equations has been solved in uniform and spatially restricted cases. The phase transition occurs at a certain threshold pump, the value of which decreases if temperature of a sample approaches to the critical temperature. The dynamics of the transition has a retardation interval, which decreases with a pump rising.