Dokl. Akad. Nauk SSSR, 1982 Volume 267, Number 5,Pages 1106–1109(Mi dan45807)
PHYSICS
Cascade laser generation of $\mathrm{Er}^{3+}$ ions in crystals of $\mathrm{YAlO}_3$ according to the scheme
$^4S_{3/2}\to^4I_{9/2}\rightsquigarrow^4I_{11/2}\to^4I_{13/2}$