Spectroscopic properties of neodymium-activated scandium garnets

The Czochralski method was used to synthesize neodymium-activated mixed garnets Gd 3 Sc 2 Al 3 O 12 and Gd 3 (GaSc) 5 O 12 . An analysis of the optical spectra yielded the crystal splitting schemes of the 4 F 3/2 , 4 I 9/2 , 4 I 11/2 levels of Nd 3+ . The kinetics of decay of the metastable state of Nd 3+ in these compounds was investigated for various activator concentrations. It was found that, when the Nd 3+ concentration was 5 wt. % in Gd 3 Sc 2 Al 3 O 12 and 2 or 5 wt. % in Gd 3 (GaSc) 5 O 12 , this decay was affected considerably by the direct donor-acceptor interaction, which resulted in nonradiative loss of the excitation.