Fig. 1. Model diagram of two-stage pumping system with Fresnel lens-vase pumping cavity

Fig. 2. Optimization scheme of bottle-shaped cavity and selection of window position. (a) Schematic of vase cavity optimization; (b) relationship between window position and input power

Fig. 3. Absorption power and absorption ratio corresponding to different apertures

Fig. 4. Axial power density of crystal rods with different waist widths

Fig. 5. Input power and variance of axial power density distribution of different waist widths

Fig. 6. Axial power density of different lengths

Fig. 7. Input power and variance of axial power density distribution of different crystal rod lengths

Fig. 8. Axial power density of different exit window apertures

Fig. 9. Input power and variance of axial power density distribution of different exit window apertures

Fig. 10. Output power and variance of axial power density distribution of different bottle waist heights

Fig. 11. Model diagram of two-stage pumping system with Fresnel lens-conic pumping cavity

Fig. 12. Axial temperature distribution of crystal rods with different pumping cavities