| Popis: |
In order to output the ideal infrared fluorescence matrix glass,a serial of chalcogenide glasses based on Ge-Ga-S-KBr system doped with different Er3+ concentrations are synthesized by a melt-quenching technique.The refractive indexes,absorption spectra,mid-infrared emission spectra of samples are measured.The oscillator strengths of absorption lines of Er3+ ions are calculated using the absorption spectra.The intensity parameters(Ωi,i=2,4,6),transition probabilities(A),branching ratios(β) are predicted for Er3+ ions in the samples using the Judd-Ofelt theory.The mid-infrared emission properties are investigated for the samples with the different Er3+ concentrations under 808 nm laser excitation.The 2.8 μm-emission cross-section is calculated using the theory of the Futchbauer-Ladenburg.The results indicate that the fluorescence under 808 nm excitation with peak wavelength at 2.8 μm is due to the Er3+∶4I11/2→4I13/2 transition.The intensity of the mid-infrared fluorescence is enhanced by increasing the concentration of the Er3+ from 0.4 wt% to 1.0 wt%.Multiphonon relaxation rate is estimated to be 37 s-1 for the Er3+∶4I11/2 level. |
