Fig. 1. Schematic diagram of deep UV femtosecond laser

Fig. 2. Schematic diagram of single pass amplification

Fig. 3. Structure diagram of deep UV femtosecond laser

Fig. 4. (a) Femtosecond pulse spectrum before frequency doubling; (b) Deep UV femtosecond pulse spectrum after frequency doubling

Fig. 5. Schematic diagram of enlarged optical path

Fig. 6. Schematic diagram of two-photon fluorescence pulse width measurement system^[31]

Fig. 7. Two-photo fluorescence image and the fitting results. (a) The reflected light path increases the quartz sheet delay; (b) No delay; (c) The transmitted light path increases the quartz sheet delay

Fig. 8. Optical pulse signal of femtosecond laser. (a) Delay setting of femtosecond signal; (b) Monopulse waveform; (c) Jitter of femtosecond optical pulse

Fig. 9. Optical pulse signal of excimer amplifier. (a) Excimer internal delay; (b) Monopulse waveform; (c) Signal drift of excimer light pulse within 30 min; (d) Jitter of excimer pulse

Fig. 10. Synchronization signal. (a) Monopulse waveform; (b) Signal drift of excimer light pulse within 30 min; (c) Jitter of synchronization signal

Fig. 11. Fitting results of pulse energy with time delay after amplification

Fig. 12. Variation of two-photon fluorescence with time delay

Fig. 13. Relationship between pulse width and discharge delay