Dokl. Akad. Nauk SSSR, 1974 Volume 216, Number 4,Pages 767–768(Mi dan38342)
PHYSICS
Stimulation of $\mathrm{Nd}^{3+}$ ion radiation in thecrystal
$\mathrm{Sr}\mathrm{Al}_{12}\mathrm{O}_{19}$ on the transitions $^4F_{3/2}\to^4I_{11/2}$
and $^4F_{3/2}\to^4I_{13/2}$