Channel waveguide formed by multi-energy O2+ ion implantation with different doses is analyzed at both 633 and 1539 nm. It has been demonstrated that the transverse mode number of waveguide is governed by the practical width of the channel waveguide, which depends on not only the channel width from pattern mask, but the lateral straggling of implanted ions. Beam propagation method (BPM) is employed to simulate the possible propagation transverse mode in the waveguides with different widths. The results at 1539 nm show that the waveguide keeps being a single mode waveguide until the width of channel is greater than 15 μm. At 633 nm, TE20 mode can be obtained even the width of channel is very small, and the TE30 mode begins to appear when the width is greater than 9 μm. These simulation results are in good agreement with the experimental results and the calculated results from Marcatilis method.
