Optimization of the pulse width and injection time in a double-pass laser amplifier

Abstract

We have optimized the input pulse width and injection time to achieve the highest possible output pulse energy in a double-pass laser amplifier. For this purpose, we have extended the modified Frantz-Nodvik equation by simultaneously including both spontaneous emission and pump energy variation. The maximum achieved fluence of the output pulse was 2.4 J/$c{m}^2$. An input pulse energy of 1 J could be maximally amplified to output pulse energy of 12.17 J, where the optimal values of the pulse width and injection time of the input pulse were 168 μs and 10 μs, respectively, with the effective pump energy being 8.84 J.