ND3+ MULTISITES IN THE DISORDERED CA3GA2GE3O12 LASER CRYSTAL

Laser excited site-selective spectroscopy of Nd3+ ions in Ca3Ga2Ge3O12 garnet crystals has been investigated in the F-4(3/2)-->I-4(11/2) and F-4(3/2)-->I-4(9/2) regions. Six non-equivalent sites were observed f or the Nd3+ in this material. The energy levels of some relevant multi plets were obtained for each Nd3+ site. The evolution of the non-equiv alent Nd3+ CryStal field sites in Ca3Ga2Ge3O12 as a function of dopant concentration has been investigated in the range up to 8 at%. The nat ure of the Nd3+ sites in terms of the possible charge compensating def ects is discussed. The formation of Nd3+-Nd3+ pairs is suggested.