Fig. 1: Laser activation of tin-related defect centres.

a Schematic illustrating the process of ion implantation followed by femtosecond laser annealing. Tin (Sn¹¹⁷) ions are implanted into the diamond lattice and, as a side effect, create lattice damage in the form of carbon vacancies and self-interstitials. Subsequent laser treatment activates negatively-charged tin vacancies (SnV⁻) and other defect centres. The two insets show photoluminescence (PL) images with fluorescent alignment markers before and after preliminary laser treatment, respectively. The measurement was performed at room temperature using only a 532 nm notch filter to block the PL excitation laser. b Example spectra from an implantation site with 500 ions at three different stages: immediately after ion implantation (top), after preliminary laser treatment (middle), and after 2 h of extended laser annealing (bottom). Highlighted areas are the spectral windows of interest for Type II Sn (blue), SnV⁻ (orange), and neutral carbon vacancies (GR1, red). I_max is the peak spectral intensity of the bottom spectrum. c PL images of four regions with different ion implantation dosages after preliminary laser treatment. The spectral collection window is 615–625 nm. d−f Spectrally integrated emission intensity of Type II Sn-related, SnV⁻-related, and GR1-related defects, respectively, as a function of implantation dosage following the extended laser annealing. Error bars indicate one standard error. Dashed lines are linear fits to each data set on the double logarithmic scale with slopes 0.31 ± 0.05, 0.59 ± 0.27, and 0.89 ± 0.15, respectively.