Judd-Ofelt analysis and improvement in thermal stability and optical properties of Er3+ doped TeO2-ZnO-Na2O-B2O3-GeO2 glasses

Er3+ doped TeO2-ZnO-Na2O-B2O3-GeO2 glasses were elaborated by melt quenching method with powders being immersed in CCl4 that served as a reagent of dehydration. The structure has been investigated by means of Fourier transform infrared spectroscopy. Differential scanning calorimetry and thermal mechanical analysis determined thermal parameters. It is found that glasses obtained from the present work have high thermal stability against crystallisation. The difference of crystallisation temperature T-x and glass transition temperature T-g is >155 degrees C and the thermal expansion a is in the range of 8.668 x 10(-6) -12.279 x 10(-6) degrees C-1. The theories of JuddOfelt and McCumber are applied to analyse the optical spectra. Intensity parameter Omega(lambda) (lambda=2, 4 and 6), transition probability A(ed), radiative lifetime tau(i) and branching ratio beta of the Er3+ transitions were obtained. The emission cross-sections sigma(emis) of Er3+ : (4)vertical bar 1(3/2) -> (4)vertical bar 1(5/2) transitions have been calculated. All the above parameters indicate that the properties of Er3+ doped TeO2-ZnO-Na2O- B2O3-GeO2 glasses have been improved effectively in the present work. The glass can be used as ideal material for optical amplifiers.