Faculty Publications

Title

Analyses of 4f11 Energy Levels and Transition Intensities Between Stark Levels of Er3+ in Y3 Al5 O12

Document Type

Article

Publication Date

January 2010

Abstract

Absorption and fluorescence spectra obtained at temperatures as low as 4 K were investigated between 200 and 1550 nm on samples containing approximately 1.2 at. wt. % Er in Y3 Al5 O12 (YAG). Within this wavelength range 125 experimental energy (Stark) levels were analyzed, representing data that span 29 2S+1 LJ multiplet manifolds of Er3+ (4f11) in D2 sites up to an energy of 44,000 cm-1. Agreement between calculated and observed Stark levels was achieved with an r.m.s. deviation of 11.2 cm-1. These transitions originate from the ground-state Stark level in the 4I 15/2 manifold to J+1/2 Stark levels associated with each of the 28 excited-state manifolds. A total of 88 ground-state absorption transition line strengths were measured for 19 2S+1 LJ multiplet manifolds between 280 and 1550 nm. For line strength measurements, the Er3+ ion is assumed to be distributed homogeneously throughout the D2 cation sites of Y3+ in the lattice. The line strengths were analyzed with a weighted (Ei - Ci)/Ei, with an r.m.s. error of 0.25. Use of a ‘‘vector crystal field’’ parametrization resolves ambiguities in the transition intensity parameters and allows for the definition of polarization-resolved Judd-Ofelt parameters, which may have wide-ranging applicability for future Judd-Ofelt-type intensity calculations.

Journal Title

Spectroscopy Letters

Volume

43