SPECTROSCOPIC AND 2-PHOTON UP-CONVERSION STUDIES OF HO3-DOPED LU3AL5O12()

A detailed spectroscopic investigation of Lu3Al5O12 doped with Ho3+ ha s been performed. Judd-Ofelt intensity parameters are estimated as Ome ga(2) = 0.172 +/- 0.10 x 10(-20) cm(2), Omega(4) = 2.08 +/- 0.18 x 10( -20) cm(2), and Omega(6) = 1.92 +/- 0.11 x 10(-20) cm(2). Transition p robabilities and lifetimes were also estimated. Experimentally, we fou nd that Ho3+ ion occupies more than one type of site in the lattice. E nergy upconversion studies were performed under different laser excita tion conditions. (C) 1998 Elsevier Science B.V. All rights reserved.