Spectroscopic properties of Nd 3+ in fluoroaluminate glasses for an efficient 1.3 μm optical amplifier

Abstract

In the majority of Nd 3+-doped glasses the amplifier gain is shifted out of the second telecom window (1.3 μm) as a result of long-wavelength emission and signal excited-state absorption (ESA). In this paper we describe new fluoroaluminate glasses developed as hosts for the 1.3 μm Nd 3+-doped fibre amplifier. Nd 3+ emission peaks at 1310–1317 nm were demonstrated in glasses. Gain in the 1310–1320 nm region was measured in unclad fibres, with evidence of reduced ESA. The paper also examines thermal and viscous properties of the core and cladding glasses for preform and fibre fabrication.