Arsenic sulfide single mode fibres for 1.3 μm amplification.

Praseodymium doped arsenic sulfide based single mode fibres were prepared for 1.3 μm amplification. Despite of the high maximum gain coefficient (0.5 dB mW ⁻¹ ) the pump power stability limits the suitability of this glass matrix type for amplifier and laser applications. A 1.2 mol% germanium doped single mode fibres show a maximum pump power density limit of <15 kW cm ⁻² . Investigations by pulsed pumping show that material degradation effects consist of reversible and irreversible portions, depending on the power pump density. By increasing the germanium concentration to more than 10 mol% the power stability limit can be remarkably improved. This indicates that the power sensitivity is determined by the main component arsenic sulfide in first place.