The monomode enhanced-index LiNbO(3) waveguide excited at 1540 nm is reported. X-cut LiNbO(3) crystals were implanted at room temperature by 6.0 MeV C(3+) ions with a dose of 2.0x10(15) ions/cm(2). Low loss planar optical waveguides were obtained and characterized by the prism coupling technique. Four dark modes were observed for extraordinary light at 633 nm, while only one enhanced-index mode was observed at 1540 nm. The propagation loss of the waveguide is 1.01 dB/cm measured with the moving fiber method. Reflectivity calculation method (RCM) was applied to simulate the refractive index profiles in waveguide. The width of waveguide structure induced by carbon ion implantation is ~3.6 microm.