It has been shown that a local region with an increased concentration of a nonpolymerizable component can be formed in a photopolymerizable composite layer via a diffusion process stimulated by the motion of the area of initiating illumination. Furthermore, it has been demonstrated that this region can be transferred to a given place of the polymerized material. The dependences of the formation path, width, and amplitude of the local inhomogeneity of the nonpolymerizable component on the velocity of the boundary of illumination area along the polymerized layer have been determined by numerical simulation. The results of the experiment have been presented.