Fig. 1. Schematic of beam crosstalk

Fig. 2. Schematic of beams passing through lens and grating

Fig. 3. Schematic of equivalent cavity of grating-external cavity spectral beam combining (SBC) system

Fig. 4. Intensity distribution of feedback to sub-unit itself, and the variations of feedback intensity, combined beam efficiency and beam quality factor with maximum divergence angle. (a) Intensity distribution at maximum divergence angle of 6 mrad; (b) intensity distribution at maximum divergence angle of 12 mrad; (c) variation of feedback intensity with maximum divergence angle; (d) variation of combined beam efficiency (η) and beam quality factor (M²) with maximum divergence angle

Fig. 5. Intensity distribution of feedback to array plane, and variations of cross beam feedback intensity, combined beam efficiency and beam quality factor with maximum deflection angle Φ_max.(a) Intensity distribution when Φ_max=0.65 mrad; (b) intensity distribution when Φ_max=1.00 mrad; (c) intensity distribution when Φ_max=1.24 mrad; (d) variation of crosstalk beam feedback intensity with Φ_max; (e) variation of combined beam efficiency and beam quality factor with Φ_max

Fig. 6. Intensity distribution of feedback to LD array plane under different Φ_max values. (a) Φ_max=0.95 mrad; (b) Φ_max=1.00 mard; (c) Φ_max=1.05 mrad

Fig. 7. Variations of combined beam efficiency and beam quality factor in maximum divergence angle θ_max and maximum deflection angle Φ_max. (a) Combined beam efficiency; (b) beam quality factor

Fig. 8. Influence of system parameters on combined beam efficiency. (a) Influnce of transform lens focus; (b) influence of distance Δp between adjacent emitters; (c) influence of grating line density d_s