Optical properties of stoichiometric LiNbO3 waveguides formed by low-dose oxygen ion implantation

Abstract

The planar waveguides in z-cut stoichiometric LiNbO3 crystal have been fabricated by 3.0 MeV oxygen ion implantation with the dose of 6×1014ions∕cm2 at room temperature. The modes of the waveguides were measured by the prism-coupling method with the wavelength 633 and 1539 nm, respectively. The refractive index profiles of the waveguides were reconstructed using reflectivity calculation method. The Rutherford backscattering/channeling technique was used to investigate the damage produced by the ion implantation, the minimum yield of the spectra was 4.52%. The propagation loss of waveguide was 0.61 dB/cm obtained by fiber probe technique. It was found that positive changes of extraordinary refractive indices happened in the guiding regions, and such change increased after the annealing treatment at 260 °C for 60 min.