Judd-Ofelt analysis of the Er3+ (4f11) absorption intensities in Er3+-doped garnets

Spectroscopic and laser properties of three different Er3+-doped garnet systems are characterized by employing the Judd-Ofelt (JO) analysis. The three garnet hosts are Y3Al5O12(YAG), Y3Sc2Ga3O12(YSGG), and Gd3Ga5O12(GGG). The JO model has been applied to the-room temperature absorption intensities of Er3+ (4f(11)) transitions to establish the so-called JO intensity parameters: Omega(2), Omega(4), and Omega(6) in the three garnet hosts. The intensity parameters are used to determine the radiative decay rates (emission probabilities of transitions) and branching ratios of the Er3+ transitions from the excited state J manifolds to the lower-lying J' manifolds. The predicted decay rates and branching ratios of these Er3+ transitions in YAG, YSGG, and GGG hosts are compared. From the radiative decay rates; the radiative lifetimes of the Er3+ excited states,are determined in the three garnets and are also compared. We also report the spectroscopic quality factors, Omega(4) Omega(6), obtained for the three garnets. The quantum efficiencies of the I-4(13/2) --> I-4(15/2) Er3+ transition in YAG, YSGG, and GGG are determined to be similar to79%, 82%, and 85%, respectively. (C) 2003 American Institute of Physics.