physica status solidi (b)The stimulated emission of Er3+ ions in Caf2 at λ1 = 8456 Å and λ2 = 8548 ÅYu. K. Voron’ko, Vladimir A. SychugovPublished Jan 1, 1968• 9 citationsPublisherDOI10.1002/pssb.19680250248