Optical transitions and absorption intensities of Dy3+ (4f9) in YSGG laser host

Spectroscopic and laser properties of Dy3+-doped in Y3Sc2Ga3O12 (YSGG) are characterized by employing the Judd-Ofelt theory. The Judd-Ofelt model has been applied to the room temperature absorption intensities of Dy3+ (4f(9)) transitions to obtain the three phenomenological parameters (referred to as Judd-Ofelt intensity parameters), from which the spectroscopic quality factor for Dy3+ in YSGG is determined to be 0.68. The intensity parameters are used to determine the radiative decay rates (emission probabilities), radiative lifetimes, and branching ratios of the Dy3+ transitions from the excited state manifolds to the corresponding lower-lying multiplet manifolds. Using the radiative decay rates for the Dy3+ transitions between the excited states and the lower-lying manifold states in YSGG, radiative lifetimes of the excited states are determined. The room temperature fluorescence lifetimes of the F-4(9/2) --> H-6(13/2) and F-4(9/2) --> H-6(15/2) transitions of Dy3+ in YSGG are measured to approximately 1.5ms. We have calculated the radiative lifetime of 2.36ms for the F-4(9/2) manifold state using the Judd-Ofelt model. Therefore, the quantum efficiency of Dy3+ in YSGG is determined to be approximately 59%. (C) 2003 Elsevier B.V. All rights reserved.