Effect of niobium oxide introduction on erbium luminescence in borophosphate glasses

Abstract

Abstract The role of the addition of niobium oxide in large amount on the Er 3+ emission properties at 1535 nm for excitation at 980 nm in borophosphate glass has been investigated. An increase of the emission, associated with a decrease of the lifetime of the 4 I 13/2 erbium level and a larger absorption cross section of erbium and ytterbium at 980 nm was evidenced. Changes induced on hydroxyl groups absorption with addition of Nb 2 O 5 in glasses was clearly shown by IR Spectroscopy in the range 2500–3700 cm −1 . The relationship between erbium luminescence at 1535 nm, Nb 2 O 5 concentration and OH group nature in niobium borophosphate glasses has been discussed. A fluorination treatment, conducted to reduce the OH group content, has allowed the reduction of the absorption coefficient at 3000 cm −1 by half. Amplification measured at 1535 nm has confirmed the beneficial effect of the Nb 2 O 5 introduction on the gain and has been found to be in accordance with the evolution of the luminescence properties.