Intense optical activation of Eu-doped KTiOAsO4 crystal induced by ion implantation

We report on the optical activation of Eu-doped KTiOAsO4 (KTA) by ion implantation and the effect on luminescence activity during lattice recovery. Optical activation of KTA crystals implanted with 400 keV Eu ions at an ion fluence of 5 × 1015 ions/cm2 is investigated. Despite a high damage level induced by the implantation, doping of Eu into KTA results in a strong photoluminescence in the temperature range from 4 K to 300 K, the strongest peak appears at 612 nm, which corresponding to the 5D0-7F2 transition. The lattice strain and Raman spectroscopy of the implanted KTA before and after annealing at 600°C and 700°C showed that the lattice defects are effectively recovered under annealing. Furthermore, the lattice damage effect on photoluminescence of ion-implanted Eu-doped KTA is negligible, indicating that ion implantation is an important method to obtain intense photoluminescence. The results reveal the optical activation properties of Eu implanted KTA and the attractiveness of its applications in waveguide quantum reservoirs.