Fig. 1. Structure of diagram external cavity spectral beam combining without output coupler

Fig. 2. Equivalent resonator of the external cavity spectral beam combining structure without output coupler

Fig. 3. (a) Feedback spot of the 0th-order diffracted beam; (b) Feedback spot of the 1st-order diffracted beam; (c) Schematic diagram of the feedback of the 0th-order and 1st-order diffracted beams

Fig. 4. (a) Influence of the feedback power and feedback radiation intensity on the distance of the HR₂; (b) Influence of the size of the slow axis of the combined beam spot on the distance of the HR₂

Fig. 5. Variation of the feedback beam intensity distribution with the distance of the HR₂

Fig. 6. Diffracted beam feedback. (a) Correct beam feedback; (b) Incorrect beam feedback

Fig. 7. Telescope diaphragm filter system in Zemax

Fig. 8. Variation of feedback power and combined slow-axis beam size with different multiple telescope systems

Fig. 9. Feedback reduction and misalignment caused by the "Smile" effect (fast axis direction)

Fig. 10. Feedback beam intensity distribution and combined beam spot as a function of severity of "Smile" effect

Fig. 11. Influence of "Smile" effect degree on feedback power and combined beam spot radius

Fig. 12. (a) Corrected feedback beam of fast-axis telescope system; (b) Corrected feedback beam and combined beam spot