Fig. 1. Single pulse energy variation law under constant high voltage mode

Fig. 2. Energy variation of pulses in Burst with different repetition rates under constant high voltage mode

Fig. 3. Recurrent neural network structure diagram

Fig. 4. Hidden layer network structure diagram

Fig. 5. Program flow chart of learning laser energy model using GRU network

Fig. 6. Maximum error between the energy calculated by GRU and the energy of the actual data set at each voltage

Fig. 7. Maximum energy error curve during training

Fig. 8. Comparison graph of single pulse energy obtained by GRU network and single pulse energy of actual data set when voltage is 1550 V. (a) Coincidence graph of test data and actual data; (b) actual data graph; (c) test data graph

Fig. 9. Comparison of laser energy and model generated energy between 1 kHz to 4 kHz repetition frequency under constant high voltage 1500 V. (a) Test data graph; (b) actual data graph

Fig. 10. Maximum error of laser energy and model generated energy between 1 kHz to 4 kHz repetition frequency under constant high voltage 1500 V