This work devoted to the fabrication of metal nanoparticles in silicon and sapphire by ion implantation and their modification by laser annealing. This approach is promising for the development of optical composite materials in the optoelectronics production technology. Composite layers were fabricated in silicon by implantation of 40-keV Cu+ ions at a dose of 1017 ion/cm2 and an ion beam current density varying from 2.5 to 10 mA/cm2. An interaction of high power excimer laser pulsed with fabricated composite layer aimed to modify the sizes and the size distribution of copper particles. It is found that the laser annealing diminishes nanoparticles in the silicon. Experimental data on laser modification may be explained by photofragmentation and/or melting of the nanoparticles in the silicon.