Abstract

Fluorescence spectra of Nd³⁺ 2% wt in CNGG (formula Ca₃(GaNb)_2−xGa₃O₁₂) were recorded at temperatures ranging from 10 and 298 K, for 0.9 μm, 1.06 μm, 1.32 μm bands. The room temperature absorption spectra from 300 to 2700 nm show broad bands structures, the 807 nm peak has α=10 cm⁻¹ with FWHM of 7 nm (8 times higher than Nd:YAG with same doping density), revealing the disordered nature of the crystalline matrix. In fact the 900 nm fluorescence spectrum at 10 K shows five distinct peaks splitted into two or three, confirming the presence of different occupation sites for Nd³⁺. The ⁴F_3/2 -> ⁴I_11/2 transition lifetime varies from 202 μs to 180 μs between 10 and 298 K. From experimental data we have calculated the emission cross-section of the ⁴F_3/2 transitions. The peak values are: 1.8×10⁻²⁰ cm² at 887 nm for ⁴F_3/2 -> ⁴I_11/2 transition, 6.5×10⁻²⁰ cm² at 1060 nm (with FWHM of 17 nm) for the ⁴F_3/2 - >⁴I_11/2 transition and 1.8×10⁻²⁰cm² at 1324 nm for the ⁴F_3/2 -> ⁴I_13/2 transition.

© 2000 IEEE