Carbon microfibers were grown from ethylene using laser assisted chemical vapor deposition. The laser power was varied. The internal structure of the carbon fibers was characterized by Raman spectroscopy at 514.5 nm using an Ar+ laser. Fibers were cast in epoxy resin and polished in order to allow a radial analysis of the cross-section. Each spectrum has been analyzed by noting the peak positions and width changes. Intensities of the G and D peaks were compared between spectra and allowed the determination of bonding conditions as well as the growth mechanism of the fibers as a function of the experimental parameters. (C) 2003 Elsevier B.V. All rights reserved.