title: Mid-infrared fluorescence, energy transfer process and rate equation analysis in Er3+ doped germanate glass.
abstract: Er(3+) doped Y2O3 and Nb2O5 modified germanate glasses with different Er(3+) concentrations were prepared. J-O intensity parameters were computed to estimate the structural changes due to the additions of Y2O3 and Nb2O5. The main mid-infrared spectroscopic features were investigated. To shed light on the observed mid-infrared radiative behavior, 975 nm and 1.53 μm emission spectra along with their decay lifetimes were also discussed. Moreover, the energy transfer processes of (4)I11/2 and (4)I13/2 level were quantitatively analyzed. In view of the experimental lifetimes, the simplified rate equation was utilized to calculate the energy transfer upconversion processes of upper and lower laser level of 2.7 μm emission. The theoretical calculations are in good agreement with the observed 2.7 μm fluorescence phenomena. Finally, the stimulated emission and gain cross sections were calculated and the results indicate that Er(3+) doped germanate glasses have great potential for mid-infrared application.
authors.affiliation: College of Materials Science and Engineering, China Jiliang University, Hangzhou 310018, PR China.
authors.forename: Tao
authors.initials: T
authors.lastname: Wei
authors.affiliation: College of Materials Science and Engineering, China Jiliang University, Hangzhou 310018, PR China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Tian
authors.affiliation: College of Materials Science and Engineering, China Jiliang University, Hangzhou 310018, PR China.
authors.forename: Fangze
authors.initials: F
authors.lastname: Chen
authors.affiliation: College of Materials Science and Engineering, China Jiliang University, Hangzhou 310018, PR China.
authors.forename: Muzhi
authors.initials: M
authors.lastname: Cai
authors.affiliation: College of Materials Science and Engineering, China Jiliang University, Hangzhou 310018, PR China.
authors.forename: Junjie
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Institute of Optoelectronic Technology, China Jiliang University, Hangzhou 310018, PR China.
authors.forename: Xufeng
authors.initials: X
authors.lastname: Jing
authors.affiliation: College of Materials Science and Engineering, China Jiliang University, Hangzhou 310018, PR China.
authors.forename: Fengchao
authors.initials: F
authors.lastname: Wang
authors.affiliation: State Key Lab of Luminescent Materials and Devices, and Institute of Optical Communication Materials, South China University of Technology, Guangzhou 510641, P.R. China.
authors.forename: Qinyuan
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: College of Materials Science and Engineering, China Jiliang University, Hangzhou 310018, PR China.
authors.forename: Shiqing
authors.initials: S
authors.lastname: Xu