Fig. 1. Schematic diagram of coupling system

Fig. 2. Schematic diagram of the optic switch coupling

Fig. 3. Optical path diagram of coupling system

Fig. 4. System temperature distribution without water cooling: (a) Input power is 1 W; (b) Input power is 12 kW

Fig. 5. Curve of the maximum temperature rise of the lens and variation rate of focal spot radius with the input power without water cooling

Fig. 6. Schematic diagram of circulating flow cooling method

Fig. 7. (a) Curve of maximum temperature rise of lens with input power under different water temperatures; (b) Curve of variation rate of focal spot radius with input power under different water temperatures

Fig. 8. (a) Curve of maximum temperature rise of lens with input power under different water velocities；(b) Curve of variation rate of focal spot radius with input power under different water velocities

Fig. 9. Curve of maximum temperature rise of the lens and variation rate of focal spot radius with the input power（The water temperature is 20 ℃, the water velocity is 0.01 m/s）

Fig. 10. (a) Physical device of the optic switch; (b) Schematic diagram of experiment

Fig. 11. Diagram of experimental result of coupling efficiency test

Fig. 12. Diagram of long-time stability test result of the optic switch

Fig. 13. (a) BPP stability test result of output beam of optic switch；(b) Final quality test result of output beam of optic switch