Multiwavelength gain flatness assessment of fluoride-based fibre amplifiers using a circulating loop

Using an 8 channel multiplex ranging over 28 nm and a circulating loop, the gain excursion and the signal-to-noise ratio discrepancies between channels were measured against the number of in-line fluoride-based fibre amplifiers. 27 nm 6 dB gain bandwidth was observed after six fluoride-based amplifiers