1.58 µm band fluoride-basedEr ³⁺ -doped fibre amplifier for WDMtransmission systems

Abstract

An Er3+-doped fluoride-based fibre amplifier (F-EDFA) with flat amplification characteristics in the range 1565–1600 nm was constructed for the first time. This provided a 5 nm wider flat amplification range than a silica-based Er3+-doped fibre amplifier (S-EDFA). A flattened signal gain of 30 dB was achieved with a gain excursion of 0.9 dB for a WDM signal in this wavelength range. The Er3+-doped fluoride fibre (F-EDF) which achieved a signal gain of over 30 dB without any noise figure degradation had a shorter optimum length than Er3+-doped silica fibre (S-EDF). Furthermore, F-EDF extended the amplification wavelength in the longer wavelength range by 2 nm compared with S-EDF.