Analysis and Determination of Refractive Index Profiles of O²⁺ Ion-Implanted LiNbO₃ Planar Waveguide Using Etching and Ellipsometry Techniques

The refractive index profiles of 3MeV O²⁺ ion-implanted planar waveguides in lithium niobate are reconstructed based on etching and ellipsometry techniques. SRIM2003 code is used to simulate the damage distribution in waveguide. It is demonstrated that the index profile of this kind of waveguide, extending to several micrometres in depth, can be determined by
etching in combination with following ellipsometric measurements. A good agreement is found between the simulated damage distributions in waveguide and the index profiles based on experimental data, and the
width of refractive index barrier is wider than the result of SRIM2003.