Fig. 1. Schematics of side-pumped polygonal thin-disk gain medium. (a) Pumping structure; (b) crystal structure; (c) transmission path of pump light

Fig. 2. 3D diagram of beam-shrinking coupling structure and two-dimensional pump light intensity distributions before and after beam shrinking

Fig. 3. Schematics of side pumping at different medium cutting angles. (a) 90°；(b) 45°

Fig. 4. Distribution matrix of volume element absorbed flux in gain medium

Fig. 5. Two-dimensional normalized flux distributions of pump light on different sections in gain media with different cutting angles. (a) 90°；(b) 45°

Fig. 6. Absorption flux distribution curves of pump light in gain media with different cutting angles. (a) Radial；(b) axial

Fig. 7. 2D diagrams of temperature distributions in front face and axial direction of gain media with different cutting angles. (a) 90°；(b) 45°

Fig. 8. Surface temperature distributions of polygonal gain media with different cutting angles . (a) Radial; (b) axial

Fig. 9. Absorption flux distributions of pump light. (a) Simulation result; (b) measurement result of fluorescence distribution

Fig. 10. Experimentally measured surface temperature of crystal (unit: ℃)

Fig. 11. Experimentally measured peak-valley values and RMS values of thermal wavefront distortion of gain medium

Fig. 12. Experimentally measured slope efficiency of laser oscillator

Fig. 13. 3D distribution of beam intensity of oscillator output laser