Fig. 1. Schematic view of the energy diagnostic system of the large-aperture High Power Laser Experiment Platform.

Fig. 2. After-crystal energy relationship diagram.

Fig. 3. Comparison of the energy balancing relationship between the two approaches. (a) the relationship curve between $\Sigma =h_{1}W_{1}+h_{2}W_{2}+h_{3}W_{3}$ and energy reading from three-wavelength calorimeter reading $W_{4}$ and (b) their corresponding relative errors.

Fig. 4. Comparison between the energy balancing relationships from two approaches. (a) The relationship curve between $A={K}'_{1} W_{1}+{K}'_{2} W_{2}+{K}'_{3}W_{3}$ and energy reading from the 420 calorimeter, $E_{420}$, in back of the third-harmonics sampling mirror 1 and (b) their corresponding relative errors.

Fig. 5. The relationship curve (a) between the total output energy from calibration and that derived from the main amplifier, and (b) their corresponding relative errors.

Fig. 6. Under different harmonics conversion efficiencies, the relationship curve between (a) the main amplifier energy and the total output energy from the crystal, and (b) their corresponding relative errors.