Laser excited site-selection spectroscopy of Nd3+ ion in the Ca3Ga2Ge3
O12 laser garnet crystal has been investigated for the transitions Z1
(I9/2)-->D1(4G5/2) and F-4(3/2) --> I-4(9/2) in order to understand th
e nature of the different Nd centers in terms of the possible charge c
ompensating defects. Lifetime data of the F-4(3/2) --> I-4(9/2) transi
tion obtained as a function of Nd concentration have allowed to distin
guish the Nd3+ ions compensated by Ga3+ ions (Nd3+(Ca2+)-Ga3+(Ge4+)) f
rom other kind of Nd3+ ions, which can be presumably associated with N
d3+ (Ca2+)-Nd3+(Ge4+) pairs.