Fig. 1. Typical variation curve of R versus F obtained by simulation when the gain medium is located at one end of the active cavity

Fig. 2. Sketch of experimental setup

Fig. 3. When the cavity length is 45 mm, the curve of output power changed with pump power and the near-field spots at different output powers

Fig. 4. Curve of output power changed with pump power when the cavity length is 40 mm and the near-field spots at different output powers

Fig. 5. Simulated curves of the spot radius on the gain chip changed with the thermal focal length of F1 under different cavity lengths. (a) 45 mm; (b) 40 mm

Fig. 6. Observation orientation and results of the fluorescence spectra of the gain chip. (a) Schematic of the fluorescence wavelength observation at different angles; (b) comparison of the fluorescence spectra at 0°, 45°, 60°, and 90°

Fig. 7. Schematic and output curve of VECSEL using V-shaped cavity. (a) System setup diagram; (b) V-cavity output curve and spots