Thermal stability and spectroscopic properties of erbium-doped tellurite glass

分析了掺Er^3+碲酸盐玻璃的热力学稳定性能，研究了掺Er^3+碲酸盐玻璃的吸收和荧光光谱性质；应用Judd-Ofelt理论计算了碲酸盐玻璃中Er^3+离子的强度参数Ω(Ω2=4．79×10^-20cm^2,Ω4=1．52×10^-20cm^2，Ω6=0．66×10^-20cm^2)，计算了离子的自发跃迁几率，荧光分支比；应用McCumber理论计算了Er^3+的受激发射截面(σe=10．40×10^-21cm^2)、Er^3+离子^4I13／2→^4I15／2发射谱的荧光半高宽(FWHM=65．5nm)Er3+-doped tellurite glasses with various Na2O/K2O ratios were prepared by conventional glass melting. Glass transition temperature T-g and crystallization temperature T,, were tested by DSC. The effect of mixed alkali on thermal stability of tellurite glasses was described. The results show that the mixed alkali is beneficial to tellurite glasses on thermal stability and the best mixed alkali molar ratio is Na2O/K2O=1/4. According to absorption spectra, Judd-Ofelt intensity parameters were determined and used to calculate the radiation rates, fluorescent branch ratio and radiative lifetimes of Er3+ in tellurite glasses. The J-O parameters were obtained, Omega(2)=4.79x 10(-20)cm(2), Omega(4)=1.52x 10(-20)cm(2), Omega(6)=0.70x 10(-20)cm(2). The stimulated emission cross sections (sigma(e)=10.40x 10(-21)cm(2)) of the Er3+ ion 4I(13/2) ->I-4(15/2) transition was calculated by the McCumber theory. The FWHM(FWHM=65.5nm) of the 4I(13/2) -> 4I(15/2) emission and lifetimes of every level of Er3+ ion were measured and the lifetime of 4I(13/2) level is 3.99ms. The spectroscopic properties of Er3+ ion were compared in different glasses. The conclusions indicate that tellurite glass is much more beneficial for optical fiber amplifier to realize broadband and high gain amplification