2-3 ?M Spectroscopic Properties Of Rare Earth Ions Doped Tellurite Glasses

2-3 ?m wavelength region has been extensively investigated driven by various applications,and development of this band of laser gain materials has become one of the hot spots in scientific research.In rencent years,the research focus of the glass hosts used to achive the lasers has already transferred from silica glasses and fluoride glasses to heavy metal oxide glasses.Tellurite glass as a kind of heavy metal oxide glass,which has good physical and chemical properties,relatively low phonon energy,high rare earth ion dissolving capacity,and other advantages.It has become a mid-infrared glass matrix material with great potential for application.The main research of this paper is as follows:Firstly,the tellurite glasses with different content of components were prepared by high-temperature melting method.The 67%TeO2-17%B2O3-16%BaO glass has relatively good thermal stability and less hydroxyl content by Raman spectroscopy,differential thermal analysis,XRD test,transmission spectrum and other test analysis.The results suggest that the composition can be used as mid-infrared emission glass host.Secondly,the glasses of 67%TeO2-17%B2O3-16%BaO system doped with Er2O3 have been researched.The relevant spectral parameters were calculated by absorption spectroscopy and J-O theoretical analysis.The effect of Er3+ concentration on 3 ?m spectroscopic properties is discussed.The fluorescence peaks appeared at 1.5 ?m and 3.0 ?m,which corresponding to the transitions of the Er3+:4I11/2?4I1s/2 and 4I11/2?4I13/2 energy levels,respectively,were found by the fluorescence spectrum.The fluorescence intensity changed with different Er2O3 doping concentrations,when Er2O3 concentration was 2 mol%,3 ?m emission intensity was the highest.Thirdly,2 ?m spectroscopic performances were investigated in Tm3+/Ho3+codoped tellurite glasses.Judd-Ofelt intensity parameters and related spectral parameters were calculated and discussed by J-O theory and absorption spectra.The radiative transition probablity of Ho3+:4I7?4I7?5I8 in TBBTH1.0 is 185.85 s-1.The fluorescence peaks appeared at 1.8 ?m and 2.0 pm,which corresponding to the transitions of the Tm3+:3F4?3H6 and Ho3+:5I7?I8 energy levels,respectively,were found by the fluorescence spectrum.In the Tm3+/Ho3+ co-doped samples,the 1.8 ?m Tm3+ fluorescence peak reduces in intensity while the Ho3+?2?m peak grows as the Ho3+ concentration increases,and this demonstrates the Tm3+ to Ho3+ energy transfer process.The highest gain in 2 ?m region could be achieved from the tellurite glass with 1 mol%Tm2O3 and 1 mol%Ho2O3.The maximum absorption cross section of Ho3+ at 1944 nm is calculated to be 5.76 ×10-21 cm2,and the maximum emission cross section at 2050 nm is 5.79 × 10-21 cm2.The gain coefficient was also calculated.The results show that the glass of Tm3+/Ho3+ codoped TeO2-B2O3-BaO glass system was a potential mid-IR laser matrix material.