Er3+ doped boro-tellurite glasses for 1.5 μm broadband amplification

B2O3 has been introduced in Er3+-doped tellurite glasses in order to increase their phonon energy and the multiphonon relaxation rate of the Er3+:I-4(11/2) --> I-4(13/2) transition, which will allow efficient 980 nm pumping. The inclusion of additional glass components such as GeO2 and Al2O3 has been shown to enhance the thermal stability of the borotellurite glasses. No crystallization peak (T-c) was observed in glass samples containing GeO2 and Al2O3. The suitability of these boro-tellurite glasses as host for broadband erbium-doped fiber amplifiers and their advantages over the other tellurite glasses are discussed. (C) 2003 Published by Elsevier B.V.