Judd-Ofelt analysis and luminescence property of Tm3+ in Ga2S3-GeS2-La2S3 glasses

Glasses with the compositions of 60GaS(3/2).10GeS(2).27LaS(3/2).3TmS(3/2) and 60GaS(3/2).10GeS(2).0.3TmS(3/2) in mol% were prepared and their luminescence properties were measured. Judd-Ofelt analysis was performed for the 3 mol% Tm3+-doped glass. The Omega(2) parameter was larger than those of fluoride glasses, while the Omega(4) and Omega(6) were comparable with those of oxide and fluoride glasses. Radiative transition rates of excited levels and branching ratios were calculated using the Omega parameters and reduced matrix elements. The radiative transition rates were about 10 times larger than those of oxide and fluoride glasses because of the larger refractive index of the sulfide glass. Decay curves of the emissions from F-3(3)(+F-3(2)) (695 nm) and H-3(4) (798 nm) levels were measured for the 0.3 mol% Tm3+-doped grass. Emission quantum efficiencies were 13 +/- 1% and 93 +/- 7% for the F-3(3) and the H-3(4) levels, respectively. Emission spectra in the wavelength range of 1000-1700 nm were also observed by the excitation of the F-3(3) and H-3(4) levels. (C) 2000 Elsevier Science B.V. Ail rights reserved.