Applied Physics LettersERRATA: Coherent Oscillation from Tm3+, Ho3+, Yb3+, and Er3+ Ions in Yttrium Aluminum GarnetL. F. Johnson, J. E. Geusic, LeGrand G. Van UitertPublished Oct 15, 1965• 1 citationPublisherDOI10.1063/1.1754391