Erbium doped fibres for efficient optical amplifiers

Abstract
The authors report that erbium doped Al2O3−P2O5−SiO2 based fibres can be used as efficient optical amplifiers provided the concentration of erbium is kept low. Small signal gains of 35 dB at 1.55 μm and a 3 dB bandwidth of 35 nm have been measured using 70 mW pump power at 1.475 μm. Even when driven heavily into saturation, 16 dB gain was achieved with a resultant signal output power of 15.6 dBm.