Annealing Characters of KTP Crystal Formed with He+-Ions at High Dose and Low Energy

A dose of 8 × 10¹⁶ ions/cm² He⁺ ions has been implanted into a z-cut KTP crystal with energy of 150 KeV at room temperature. The refractive index profile has been measured by the Model 2010 Prism Coupler at room temperature and after annealed at temperature of 200°C, 300°C and 400°C. The surface effective refractive index also has been obtained. The results show that the surface effective refractive index increases with annealing temperature, indicating a process of lattice structure recovery. After annealing at 400°C for 3.5 hours, the surface effective refractive index n_x, n_y is nearly to, while n_z is still much less than the refractive index of substrate KTP crystal.