title: Fluorescence dynamics and rate equation analysis in Er3+ and Yb3+ doped double tungstates.
abstract: The fluorescence dynamics in Er3+ and Yb3+ doped KGd(WO4)2 and KY(WO4)2 has been investigated. Lifetimes have been measured for the Yb (2F(5/2)), Er (4I(13/2)), and Er (4S(3/2)) levels around 1, 1.5, and 0.55 microm, respectively. The Yb (2F(5/2)) lifetimes show a decreasing trend toward the limiting Er (4I(11/2)) lifetime with increasing Er-to-Yb concentration ratio, whereas the Er (4I(13/2)) lifetimes are mostly unaffected by the doping concentrations. A rate equation analysis has been performed to explain the observed behavior and gain is calculated for a continuous-wave laser at 1.53 microm to find the optimum doping concentrations for high gain.
authors.affiliation: Department of Physics, Royal Institute of Technology, KTH, Stockholm, Sweden. sb@laserphysics.kth.se
authors.forename: Stefan
authors.initials: S
authors.lastname: Bjurshagen
authors.forename: Jonas E
authors.initials: JE
authors.lastname: Hellström
authors.forename: Valdas
authors.initials: V
authors.lastname: Pasiskevicius
authors.forename: Maria Cinta
authors.initials: MC
authors.lastname: Pujol
authors.forename: Magdalena
authors.initials: M
authors.lastname: Aguiló
authors.forename: Francesc
authors.initials: F
authors.lastname: Díaz