Fig. 1. Traditional electrical connection way and breakdown principle of LD. (a) Traditional electrical connection way; (b) breakdown principle

Fig. 2. Power supply principle of laser with electric function module

Fig. 3. Output beam spot with different number of single tubes coupling. (a) Output beam spot with one chip coupled; (b) output beam spot with two chips coupled; (c) output beam spot with three chips coupled; (d) output beam spot with four chips coupled

Fig. 4. Schematic of beam splicing in single module LD

Fig. 5. Schematic of beam filling in fiber beam combiner

Fig. 6. Relationship curves between TEC cooling capability Q_c and current I

Fig. 7. Relationship curves between TEC energy efficiency ratio and current

Fig. 8. TEC temperature difference at 50 ℃ high-temperature and 25 ℃ laboratory temperature. (a) 50 ℃; (b) 25 ℃

Fig. 9. TEC flow field simulation

Fig. 10. TEC temperature distribution in two-fan and four-fan modes. (a) Two-fan mode; (b) four-fan mode

Fig. 11. Heat distribution of single module LD

Fig. 12. Physical device and power test photo

Fig. 13. Measurement curves of power and efficiency

Fig. 14. Measured spectral curves

Fig. 15. Spot measurement after imaging

Fig. 16. Experimental photos. (a) Experimental photo of high- and low-temperature test; (b) experimental photo of vibration test