We report on the fabrication and characterization of planar waveguides in an Er-doped tungsten-tellurite glass by implantation of 3.5 MeV N+ ions. Implantations were carried out in a wide fluence range of 1 . 10(16) divided by 8 . 10(16) ions/cm(2). Waveguides were characterized by m-line spectroscopy and spectroscopic ellipsometry. Irradiation-induced refractive index modulation saturated around a fluence of 8 . 10(16) ions/cm(2). Waveguides operating at 1550 nm were obtained in that material using 3.5 MeV N+ ion implantation.