Optical parameters of nd-doped gadolinium aluminium tetraborate crystals

Nd-doped gadolinium aluminium tetraborate, NdxGdxAl3(BO3)(4) (NGAB), crysta llizes with x = 0.1 in the trigonal system with point group 32, conforming space group R32. They were grown using flux method, of large sizes and good optical quality. The unit cell constants were a = 0.93057 (6) and c = 0.72 481 (3) nm, and z = 1. The measured absorption of the NGAB is compared to J udd-Ofelt (JO) theory. When applied, the JO theory of parity-forbidden elec tric-dipole transitions of rare earth ions on noncentrosymmetric sites demo nstrates good agreement. A measured band gap of the eigentransition was abo ut 4.00 eV. The fitted intensity parameters Omega(t) (t = 2, 4, and 6) were 2.446 x 10(-20), 2.266 x 10(-20) and 2.598 x 10(-20) cm(2). Both the emiss ion properties of the sub-stable F-4(3/2) state with the level lifetime of 506.20 mu s and a fluorescence spectrum col responding to the transition F- 4(3/2) --> I-4(11/2) were studied. The results indicate the pass band of la ser for potential applications in practice.