Fig. 1. Diagrammatic sketch of the laser head and mechanical structure of the water viscolizer

Fig. 2. Numerical results of surface heat transfer coefficient

Fig. 3. Numerical results of wavefront distortion

Fig. 4. (a) near-field distribution of the pump, (b) near field of output laser with 1 Hz pumping and (c) near field of output laser with 10 Hz pumping

Fig. 5. (a) near-field distribution of the pump after optimization and (b) near field of output laser

Fig. 6. Pumping distribution and near field after one-pass amplification for a ϕ35 mm disk

Fig. 7. (a) Cr⁴⁺:YAG ceramic cladded Yb:YAG crystal, (b) near field after four-pass amplification

Fig. 8. Near field picture of different size matching degree

Fig. 9. Near field picture of 18 mm×16 mm crystal pumped by 16 mm×14 mm beam

Fig. 10. Beam quality parameters of output laser