In the quest for finding a room temperature stable single photon source (SPS), defects in hexgonal boron nitride (hBN) have gained more and more attention in the previous years. This thesis studies...Show moreIn the quest for finding a room temperature stable single photon source (SPS), defects in hexgonal boron nitride (hBN) have gained more and more attention in the previous years. This thesis studies the single photon emit- ting properties of defects in a multi-layer hBN flake with a home-build confocal microscopy setup. As a reference system, nitrogen vacancy (NV) centers in nanodiamonds (NDs) are measured first, as there luminescent properties are well documented in literature. In order to improve on pre- vious work in this group, polarization selective elements are included in the optical setup. This inclusion allowed measurements of the absorption and emission dipoles of the SPSs and improved our results by (1) reduc- ing the background and (2) allowing more efficient excitation. We found that defects in hBN showed promising results in terms of single photon purity (g2(0) =0.09 ± 0.06) and brightness (35 KHz), outperforming the best single NV center (g2(0) =0.29 ± 0.07, brightness: 4 KHz). We also found that the hBN defects showed long term (up to 3000 ns) bunching behaviour, possibly related to the excitation power during measurements. This, together with the measurement of different hBN flakes, constitute interesting topics for future investigation.Show less