Figure 3.

Shot-to-shot pulse energies of (a) upper and (b) lower branches for ∼1300 shots. The intensities measured with PD_mirror are plotted as a function of that with BIM_up and BIM_lo in (a) and (b), respectively. (c) Correlation between shot-to-shot pulse energies I _up and I _lo for 100000 shots. Yellow points (26% of the total events) satisfy the condition of the normalized difference |R _d| = |2(I _up − I _lo)/(I _up + I _lo)| < 0.5 and I _up + I _lo > 0.35 µJ, while purple points (5.8% of the total events) show |R _d| < 0.1 and I _up + I _lo > 0.35 µJ.