Optical Waveguide in X-Cut LiNbO3 Crystals by MeV P+ Ion Implantation with Low Dose

Abstract

The X-cut, Y-propagation LiNbO3 crystals were implanted by 2.8 MeV P+ ions with doses of ∼1 × 1014 ions/cm2 at room temperature. Planar optical waveguides were formed by P+ implantation at doses of 1 × 1014, 2 × 1014, 3 × 1014 and 4 × 1014 ions/cm2. Contrary to high-dose ion-implanted waveguides, the extraordinary refractive index was found to increase in the guide region for implantation with low doses by the dark mode. When the light beam was coupled to the LiNbO3 waveguide which was formed by MeV P+ implantation at a dose of 1 × 1014 ions/cm2 and a following annealing at 200 °C for 30 min in air, obvious light was found propagating through the entire length of the waveguide, and Rutherford Backscattering (RBS)/channeling technique was used to characterize the lattice reconstruction of LiNbO3 crystals after the annealing treatment.