Fig. 1. Optical path schematic of the experimental

Fig. 2. (a) 1 064 nm laser output power curves at different Q-switched frequencies; (b) Beam profile at 35 kHz and 6.1 W

Fig. 3. The pulse width of fundamental laser

Fig. 4. Signal spectrum at different temperatures

Fig. 5. Comparison of experimental results and theory curves

Fig. 6. Output power curve of idler at different temperatures

Fig. 7. (a) 3.8 μm output power and conversion efficiency curves at 35 kHz; (b) Idler beam profile

Fig. 8. The pulse width of signal