Waveguide investigation in Er-implanted KTiOPO4 by MeV He ion implantation

Potassium titanyl phosphate (KTiOPO4 or KTP) was implanted by 3.0 MeV Er ions to a dose of 7.5×1014 ions cm−2 at room temperature. The damage in the as-implanted KTiOPO4 was studied by Rutherford backscattering/channeling. Photoluminescence (PL) measurement was performed at 10 K; the Er-implanted KTiOPO4 sample was annealed at 750°C for 20 min in a N2 atmosphere and then implanted by 2.8 MeV He ions to a dose of 1.5×1016 ions cm−2 at room temperature. The dark modes were measured by the prism coupling method. 14 dark modes were observed in KTiOPO4. The refractive index profile in the KTiPOP4 waveguide was theoretically analyzed. The result shows that the shape of the refractive index profile is similar to one of the nuclear energy loss distribution.