Giant laser radiation pulses from erbium-doped yttrium aluminum garnet crystals

An investigation was made of the lasing properties of $Q$-switched $YAG:Er^{3+}$ crystals $(4/_{11/2}-4/_{13/2})$. An energy of 100 mJ was obtained in the $TEM_{00}$ mode and the pulse duration was 65 nsec. Under free-lasing conditions, the efficiency was 1.25 procent and the output radiation energy 5 J. The radiation parameters were strongly influenced by the Stark splitting of the $4/_{11/2}$ and $4/_{13/2}$ active levels.