Figure 5 shows the number of damage sites detected versus the laser fluence used in the LIDT tests, which indicate how each coating met its LIDT using either the ISO 11254 damage test protocol (a) or NIF-MEL damage test protocol (b). The LIDT of the coating containing exhibited more than 25 nonpropagating damage sites, which established its damage threshold using the NIF-MEL protocol. This suggests that there is a higher defect density in the coating, which the NIF-MEL protocol, with its dense array of 2500 damage test sites, is able to detect more readily compared to the ISO 11254 protocol, with its sparse set of damage test sites. Hence, for the coating, the LIDT from the NIF-MEL protocol is lower. Despite the presence of defects, the coating still displays the highest LIDT. Interestingly, with the NIF-MEL protocol, the LIDTs of the and the coatings are the same but, as Fig. 5 shows, they meet different damage criteria; i.e., the coating has a lower number of nonpropagating damage sites, but the LIDT was met because a propagating damage site was found. The LIDT for the coating is lower using the ISO 11254 protocol because the damage threshold is based on nonpropagating damage (pits). The coating follows the same pattern as the coating: propagating damage was found at a higher damage threshold using the NIF-MEL protocol, and nonpropagating damage sites (pits) set the lower LIDT that was found using the ISO 11254 protocol. However, the coating also has a high defect density because 24 nonpropagating damage sites were found using the NIF-MEL protocol before propagating damage occurred. Since the maximum number of nonpropagating sites permitted by the NIF-MEL protocol is 25, the coating nearly reached its LIDT due to high defect density. Overall, the coatings containing and exhibit the highest defect densities, according to the NIF-MEL results, because their LIDTs are governed by the accumulation of nonpropagating sites.