Fig. 1. Structure diagram of GaN-based blue laser chip^[15]

Fig. 2. Structure and packaging of blue LD chip^[25]. (a) Schematic diagram of the blue LD structure; (b) diagram of mounting the junction-down into a TO-Φ9 mm package

Fig. 3. Schematic diagram of the LWCG high-brightness array structure and its photocurrent and current-voltage characteristics^[26]

Fig. 4. Classification of traditional beam combining^[39-41]

Fig. 5. Schematic diagram of the 500 W module configuration based on space and polarization technology^[49]

Fig. 6. Power enhancement method for the blue LD module^[49]

Fig. 7. Schematic diagram of the beam combining optical path of BWT 7×1 fiber combiner^[41]

Fig. 8. Schematic diagram of the optical path of the BWT 250 W module^[56]

Fig. 9. Schematic diagram of wavelength beam combination

Fig. 10. Schematic diagrams of the VBG scheme and its product. (a) VBG wave-locking principle diagram^[62]; (b) 1500 W high-brightness system^[63]

Fig. 11. Structural scheme for dichroic mirror beam combination^[58]

Fig. 12. Schematic diagram of the spectral beam combining system

Fig. 13. Schematic diagram of the BLADE module^[66]. (a) Overview of WBC technology; (b) comparison of SBC and WBC technologies

Fig. 14. Overview of the laser structure^[70]. (a) Schematic diagram of the system combination; (b) optical output curve

Fig. 15. Schematic diagram of the system of a 9-channel single-tube spectral beam combination along the fast axis^[67]

Fig. 16. Output power, E-O efficiency, voltage vs. current, and beam quality^[67]. (a) Power, E-O efficiency, and voltage; (b) beam quality after spectral synthesis

Fig. 17. Schematic diagram of a high-power blue LD device based on dense spectral beam combination^[71]

Fig. 18. Comparison of the brightness levels of blue light lasers^[70]