Shell shaped carbon nanoparticles were synthesized from acetylene flow injected inside an oxygen-hydrogen diffusion flame when it was irradiated with a focused beam of a CW $CO_{2}$ laser above a certain laser power and at a certain position [I]. In the present study, the evolution of carbon nanoparticles generated under laser irradiation has been investigated together with a study on the visualization of particle generating flames. The size distributions of carbon shell nanoparticles and soots have been determined by examining the images of TEM grid on which particles were captured by local thermophoretic sampling. The variations of radii of gyration and fractal dimensions of soot and shell shaped particulate aggregates are obtained at different laser powers.