The analysis of the optimal two dimensional pump energy distribution for narrower electro-optically Q-switched pulse's width

The pump energy distribution in the cross section of the gain medium of a LDA side pumped laser and the effect of the initial gain spatial distribution on the electro-optically (EO) Q-switched pulse's width are numerical studied in this paper. The simulation results show that the relatively high energy distribution at the edge of the gain medium will lead to a longer pulse width. And two ideal pump distributions, top-hat distribution and Super Gaussian distribution at part of the cross section are also analyzed. It shows that a uniform pump region at the medium center with around 50% of the medium's cross section area leads to narrower pulse width than other pump distributions with the same max initial population inversion density.