The formation of optical waveguide in KTP crystal by combining ion implantation with ion exchange

KTP planar optical waveguide was fabricated by combining He⁺ ion implantation with Rb-K ion exchange in pure RbNO3. The lattice damage induced by He⁺ ion implantation and influence of ion implantation on ion exchange waveguide were studied. TRIM'2003 code was used to simulate the process of 2.0 MeV He⁺ ion implantation, the profile of He⁺ ions concentration as well as the defective lattice versus depth were estimated. The dark mode spectra of the waveguide were measured by the prism-coupling method at wavelength 633 and 1539 nm. The refractive index profiles in the novel waveguide were reconstructed by analyzing dark mode spectra and an increased index in the waveguide region together with a decreased index barrier in damaged layer was obtained. The influence of irradiation damage on the Rb distribution was investigated and analyzed by means of RBS technique.