Optical Waveguide Formed in RbTiOPO₄ Crystal by 6.0 MeV O³⁺ Implantation

A planar optical waveguide was formed in RbTiOPO₄; crystal by 6.0-MeV oxygen ion implantation with the dose of 2×10¹⁵ ions/cm² at room temperature. Annealing at 200°C for 30 min in air is performed to improve the thermal stability of the waveguide. The dark modes of the waveguide are measured at wavelengths 633 and 1539 nm, respectively. The refractive index profiles in the guiding layer are reconstructed by using the reflectivity calculation method. TRIM'98 code was carried out to simulate the damage profiles caused by the implantation process to obtain a better understanding of the waveguide formation.