Fig. 1. Folding optical path of amplifier and structure of discharge tube

Fig. 2. Numerical simulation of optimal beam distribution under different gain distributions. (a) Small signal gain distribution with different super-Gaussian orders; (b) optimal beam intensity distribution with different gain distributions

Fig. 3. Influence of seed power and super-Gaussian orders of gain distribution on optimal beam radius

Fig. 4. Power extraction value of seed light when the super-Gaussian order of gain distribution is 2 and 8. (a1)‒(a3) Power extraction values of different seed light intensity distributions under the 2-order Gaussian gain distribution when the incident light power is 500 W, 1000 W, and 2000 W, respectively; (b1)‒(b3) power extraction values of different seed light intensity distributions under the 8-order Gaussian gain distribution when the incident light power is 500 W, 1000 W, and 2000 W, respectively