Fig. 3.

For a given energy fluctuation (−20% in the figure as reference), as the radiant exposure increases, the relative ablation deviation decreases. For all metrics at optimum fluence (as per Table 1) relative ablation deviation equals relative energy deviation. For radiant exposures beyond optimum fluence, ablation deviations are smaller than energy fluctuations (Relative ablation deviation < −20% which is the reference energy deviation). For radiant exposures lesser than optimum fluence, ablation deviations are larger than energy fluctuations (increasing slope as the radiant exposure is reduced below optimum fluence). The metric spot volume shows the most sensitive behavior for radiant exposures below optimum fluence. For all metrics, the effect of energy deviation in ablation accounts for −100% (no ablation) close to the threshold. This implies that working at a radiant exposure above and beyond the optimum value can reduce the effects of energy fluctuations on the outcomes by reducing the ablation deviations.